How do we find out angle from $x$ & $y$ coordinates?
up vote
6
down vote
favorite
I found the following sentence.
To find the angle you use the arctangent function like this, angle $=tan^{-1}left(frac{y}{x}right)$.
But I am curious, is this the only way to know the angle?
In other words, is it possible to find the angle with $sinleft(frac{y}{x}right)$, $cosleft(frac{y}{x}right)$ or $tan$.. etc?
trigonometry arithmetic
add a comment |
up vote
6
down vote
favorite
I found the following sentence.
To find the angle you use the arctangent function like this, angle $=tan^{-1}left(frac{y}{x}right)$.
But I am curious, is this the only way to know the angle?
In other words, is it possible to find the angle with $sinleft(frac{y}{x}right)$, $cosleft(frac{y}{x}right)$ or $tan$.. etc?
trigonometry arithmetic
add a comment |
up vote
6
down vote
favorite
up vote
6
down vote
favorite
I found the following sentence.
To find the angle you use the arctangent function like this, angle $=tan^{-1}left(frac{y}{x}right)$.
But I am curious, is this the only way to know the angle?
In other words, is it possible to find the angle with $sinleft(frac{y}{x}right)$, $cosleft(frac{y}{x}right)$ or $tan$.. etc?
trigonometry arithmetic
I found the following sentence.
To find the angle you use the arctangent function like this, angle $=tan^{-1}left(frac{y}{x}right)$.
But I am curious, is this the only way to know the angle?
In other words, is it possible to find the angle with $sinleft(frac{y}{x}right)$, $cosleft(frac{y}{x}right)$ or $tan$.. etc?
trigonometry arithmetic
trigonometry arithmetic
edited Sep 18 '17 at 17:46
A---B
2,26611337
2,26611337
asked Jun 16 '15 at 8:51
gmotree
44117
44117
add a comment |
add a comment |
4 Answers
4
active
oldest
votes
up vote
4
down vote
accepted
For any given point $(x, y)$, the angle say $theta$ of the line, passing through this point & the origin, with the positive x-direction is given as $$color{blue}{tantheta=frac{y}{x}}$$ While other values are given as
$$color{blue}{sintheta=frac{y}{sqrt{x^2+y^2}}}$$
$$color{blue}{costheta=frac{x}{sqrt{x^2+y^2}}}$$
How can you find out whether degree or radian?
– gmotree
Jun 16 '15 at 21:45
The angle obtained is generally in radian which can be changed in degree by multiplying by $frac{180^o}{pi}$
– Harish Chandra Rajpoot
Jun 17 '15 at 3:45
Can I get a hyperbolic function like arctanh sinh tanh.. from sine or cosine function?
– gmotree
Jun 17 '15 at 5:07
add a comment |
up vote
4
down vote
Does the picture below help you visualise this? By 'angle' we mean $theta$ below in plane polar coordinates. For some point $(x_0,y_0)$ on the plane, we can solve for $theta$ using trigonometry.
Thanks art pictures. Yes so I asking about can we know the angle from any other tri- functions.
– gmotree
Jun 16 '15 at 9:09
This answer would be improved my including the actual trig to get theta from x0 and y0 here.
– lindes
Jun 1 at 4:41
add a comment |
up vote
0
down vote
You can use one of the following three formulas to find an angle.
1)$$f(x,y)=pi-frac{pi}{1+mbox{sgn}(x)}left(1-mbox{sgn}(y^2)right)-frac{pi}{4}left(2+mbox{sgn}(x)right)mbox{sgn}(y)$$
$$-mbox{sgn}(xy)*mbox{atan}left(frac{|x|-|y|}{|x|+|y|}right)$$
2)$$f(x,y)=pi-pi/2*(1+mbox{sgn}(x))(1-mbox{sgn}(y^2))-frac{pi}{4}(2+mbox{sgn}(x))mbox{sgn}(y)$$
$$-mbox{sgn}(xy)mbox{asin}left(frac{left|xright|-left|yright|}{sqrt{2*x^2+2*y^2}}right)$$
3)$$f(x,y)=pi-frac{pi}{2}(1+mbox{sgn}(x))(1-mbox{sgn}(y^2))-frac{pi}{4}(2+mbox{sgn}(x))mbox{sgn}(y)$$
$$-mbox{sgn}(left|xright|-left|yright|)mbox{sgn}(xy)mbox{acos}left(frac{left|xright|+left|yright|}{sqrt{2*x^2+2*y^2}}right)$$
Each of the formulas give the angle from $0$ to $2pi$ for any value of $x$ and $y$.
For $x=y=0$, the result is undefined.
New contributor
Could you try to use MathJax to format the formula; as is this is hard to read. math.meta.stackexchange.com/questions/5020/…
– quid♦
2 days ago
add a comment |
up vote
0
down vote
In this recent answer, it is shown that
$$
theta=2arctanleft(vcenter{frac y{x+sqrt{x^2+y^2}}}right)
$$
This formula works for all $x,y$ except on the negative real axis, where $theta$ goes from just under $pi$ on top to just above $-pi$ underneath.
add a comment |
4 Answers
4
active
oldest
votes
4 Answers
4
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
4
down vote
accepted
For any given point $(x, y)$, the angle say $theta$ of the line, passing through this point & the origin, with the positive x-direction is given as $$color{blue}{tantheta=frac{y}{x}}$$ While other values are given as
$$color{blue}{sintheta=frac{y}{sqrt{x^2+y^2}}}$$
$$color{blue}{costheta=frac{x}{sqrt{x^2+y^2}}}$$
How can you find out whether degree or radian?
– gmotree
Jun 16 '15 at 21:45
The angle obtained is generally in radian which can be changed in degree by multiplying by $frac{180^o}{pi}$
– Harish Chandra Rajpoot
Jun 17 '15 at 3:45
Can I get a hyperbolic function like arctanh sinh tanh.. from sine or cosine function?
– gmotree
Jun 17 '15 at 5:07
add a comment |
up vote
4
down vote
accepted
For any given point $(x, y)$, the angle say $theta$ of the line, passing through this point & the origin, with the positive x-direction is given as $$color{blue}{tantheta=frac{y}{x}}$$ While other values are given as
$$color{blue}{sintheta=frac{y}{sqrt{x^2+y^2}}}$$
$$color{blue}{costheta=frac{x}{sqrt{x^2+y^2}}}$$
How can you find out whether degree or radian?
– gmotree
Jun 16 '15 at 21:45
The angle obtained is generally in radian which can be changed in degree by multiplying by $frac{180^o}{pi}$
– Harish Chandra Rajpoot
Jun 17 '15 at 3:45
Can I get a hyperbolic function like arctanh sinh tanh.. from sine or cosine function?
– gmotree
Jun 17 '15 at 5:07
add a comment |
up vote
4
down vote
accepted
up vote
4
down vote
accepted
For any given point $(x, y)$, the angle say $theta$ of the line, passing through this point & the origin, with the positive x-direction is given as $$color{blue}{tantheta=frac{y}{x}}$$ While other values are given as
$$color{blue}{sintheta=frac{y}{sqrt{x^2+y^2}}}$$
$$color{blue}{costheta=frac{x}{sqrt{x^2+y^2}}}$$
For any given point $(x, y)$, the angle say $theta$ of the line, passing through this point & the origin, with the positive x-direction is given as $$color{blue}{tantheta=frac{y}{x}}$$ While other values are given as
$$color{blue}{sintheta=frac{y}{sqrt{x^2+y^2}}}$$
$$color{blue}{costheta=frac{x}{sqrt{x^2+y^2}}}$$
answered Jun 16 '15 at 11:16
Harish Chandra Rajpoot
29.4k103671
29.4k103671
How can you find out whether degree or radian?
– gmotree
Jun 16 '15 at 21:45
The angle obtained is generally in radian which can be changed in degree by multiplying by $frac{180^o}{pi}$
– Harish Chandra Rajpoot
Jun 17 '15 at 3:45
Can I get a hyperbolic function like arctanh sinh tanh.. from sine or cosine function?
– gmotree
Jun 17 '15 at 5:07
add a comment |
How can you find out whether degree or radian?
– gmotree
Jun 16 '15 at 21:45
The angle obtained is generally in radian which can be changed in degree by multiplying by $frac{180^o}{pi}$
– Harish Chandra Rajpoot
Jun 17 '15 at 3:45
Can I get a hyperbolic function like arctanh sinh tanh.. from sine or cosine function?
– gmotree
Jun 17 '15 at 5:07
How can you find out whether degree or radian?
– gmotree
Jun 16 '15 at 21:45
How can you find out whether degree or radian?
– gmotree
Jun 16 '15 at 21:45
The angle obtained is generally in radian which can be changed in degree by multiplying by $frac{180^o}{pi}$
– Harish Chandra Rajpoot
Jun 17 '15 at 3:45
The angle obtained is generally in radian which can be changed in degree by multiplying by $frac{180^o}{pi}$
– Harish Chandra Rajpoot
Jun 17 '15 at 3:45
Can I get a hyperbolic function like arctanh sinh tanh.. from sine or cosine function?
– gmotree
Jun 17 '15 at 5:07
Can I get a hyperbolic function like arctanh sinh tanh.. from sine or cosine function?
– gmotree
Jun 17 '15 at 5:07
add a comment |
up vote
4
down vote
Does the picture below help you visualise this? By 'angle' we mean $theta$ below in plane polar coordinates. For some point $(x_0,y_0)$ on the plane, we can solve for $theta$ using trigonometry.
Thanks art pictures. Yes so I asking about can we know the angle from any other tri- functions.
– gmotree
Jun 16 '15 at 9:09
This answer would be improved my including the actual trig to get theta from x0 and y0 here.
– lindes
Jun 1 at 4:41
add a comment |
up vote
4
down vote
Does the picture below help you visualise this? By 'angle' we mean $theta$ below in plane polar coordinates. For some point $(x_0,y_0)$ on the plane, we can solve for $theta$ using trigonometry.
Thanks art pictures. Yes so I asking about can we know the angle from any other tri- functions.
– gmotree
Jun 16 '15 at 9:09
This answer would be improved my including the actual trig to get theta from x0 and y0 here.
– lindes
Jun 1 at 4:41
add a comment |
up vote
4
down vote
up vote
4
down vote
Does the picture below help you visualise this? By 'angle' we mean $theta$ below in plane polar coordinates. For some point $(x_0,y_0)$ on the plane, we can solve for $theta$ using trigonometry.
Does the picture below help you visualise this? By 'angle' we mean $theta$ below in plane polar coordinates. For some point $(x_0,y_0)$ on the plane, we can solve for $theta$ using trigonometry.
answered Jun 16 '15 at 8:57
Ruvi Lecamwasam
1,250618
1,250618
Thanks art pictures. Yes so I asking about can we know the angle from any other tri- functions.
– gmotree
Jun 16 '15 at 9:09
This answer would be improved my including the actual trig to get theta from x0 and y0 here.
– lindes
Jun 1 at 4:41
add a comment |
Thanks art pictures. Yes so I asking about can we know the angle from any other tri- functions.
– gmotree
Jun 16 '15 at 9:09
This answer would be improved my including the actual trig to get theta from x0 and y0 here.
– lindes
Jun 1 at 4:41
Thanks art pictures. Yes so I asking about can we know the angle from any other tri- functions.
– gmotree
Jun 16 '15 at 9:09
Thanks art pictures. Yes so I asking about can we know the angle from any other tri- functions.
– gmotree
Jun 16 '15 at 9:09
This answer would be improved my including the actual trig to get theta from x0 and y0 here.
– lindes
Jun 1 at 4:41
This answer would be improved my including the actual trig to get theta from x0 and y0 here.
– lindes
Jun 1 at 4:41
add a comment |
up vote
0
down vote
You can use one of the following three formulas to find an angle.
1)$$f(x,y)=pi-frac{pi}{1+mbox{sgn}(x)}left(1-mbox{sgn}(y^2)right)-frac{pi}{4}left(2+mbox{sgn}(x)right)mbox{sgn}(y)$$
$$-mbox{sgn}(xy)*mbox{atan}left(frac{|x|-|y|}{|x|+|y|}right)$$
2)$$f(x,y)=pi-pi/2*(1+mbox{sgn}(x))(1-mbox{sgn}(y^2))-frac{pi}{4}(2+mbox{sgn}(x))mbox{sgn}(y)$$
$$-mbox{sgn}(xy)mbox{asin}left(frac{left|xright|-left|yright|}{sqrt{2*x^2+2*y^2}}right)$$
3)$$f(x,y)=pi-frac{pi}{2}(1+mbox{sgn}(x))(1-mbox{sgn}(y^2))-frac{pi}{4}(2+mbox{sgn}(x))mbox{sgn}(y)$$
$$-mbox{sgn}(left|xright|-left|yright|)mbox{sgn}(xy)mbox{acos}left(frac{left|xright|+left|yright|}{sqrt{2*x^2+2*y^2}}right)$$
Each of the formulas give the angle from $0$ to $2pi$ for any value of $x$ and $y$.
For $x=y=0$, the result is undefined.
New contributor
Could you try to use MathJax to format the formula; as is this is hard to read. math.meta.stackexchange.com/questions/5020/…
– quid♦
2 days ago
add a comment |
up vote
0
down vote
You can use one of the following three formulas to find an angle.
1)$$f(x,y)=pi-frac{pi}{1+mbox{sgn}(x)}left(1-mbox{sgn}(y^2)right)-frac{pi}{4}left(2+mbox{sgn}(x)right)mbox{sgn}(y)$$
$$-mbox{sgn}(xy)*mbox{atan}left(frac{|x|-|y|}{|x|+|y|}right)$$
2)$$f(x,y)=pi-pi/2*(1+mbox{sgn}(x))(1-mbox{sgn}(y^2))-frac{pi}{4}(2+mbox{sgn}(x))mbox{sgn}(y)$$
$$-mbox{sgn}(xy)mbox{asin}left(frac{left|xright|-left|yright|}{sqrt{2*x^2+2*y^2}}right)$$
3)$$f(x,y)=pi-frac{pi}{2}(1+mbox{sgn}(x))(1-mbox{sgn}(y^2))-frac{pi}{4}(2+mbox{sgn}(x))mbox{sgn}(y)$$
$$-mbox{sgn}(left|xright|-left|yright|)mbox{sgn}(xy)mbox{acos}left(frac{left|xright|+left|yright|}{sqrt{2*x^2+2*y^2}}right)$$
Each of the formulas give the angle from $0$ to $2pi$ for any value of $x$ and $y$.
For $x=y=0$, the result is undefined.
New contributor
Could you try to use MathJax to format the formula; as is this is hard to read. math.meta.stackexchange.com/questions/5020/…
– quid♦
2 days ago
add a comment |
up vote
0
down vote
up vote
0
down vote
You can use one of the following three formulas to find an angle.
1)$$f(x,y)=pi-frac{pi}{1+mbox{sgn}(x)}left(1-mbox{sgn}(y^2)right)-frac{pi}{4}left(2+mbox{sgn}(x)right)mbox{sgn}(y)$$
$$-mbox{sgn}(xy)*mbox{atan}left(frac{|x|-|y|}{|x|+|y|}right)$$
2)$$f(x,y)=pi-pi/2*(1+mbox{sgn}(x))(1-mbox{sgn}(y^2))-frac{pi}{4}(2+mbox{sgn}(x))mbox{sgn}(y)$$
$$-mbox{sgn}(xy)mbox{asin}left(frac{left|xright|-left|yright|}{sqrt{2*x^2+2*y^2}}right)$$
3)$$f(x,y)=pi-frac{pi}{2}(1+mbox{sgn}(x))(1-mbox{sgn}(y^2))-frac{pi}{4}(2+mbox{sgn}(x))mbox{sgn}(y)$$
$$-mbox{sgn}(left|xright|-left|yright|)mbox{sgn}(xy)mbox{acos}left(frac{left|xright|+left|yright|}{sqrt{2*x^2+2*y^2}}right)$$
Each of the formulas give the angle from $0$ to $2pi$ for any value of $x$ and $y$.
For $x=y=0$, the result is undefined.
New contributor
You can use one of the following three formulas to find an angle.
1)$$f(x,y)=pi-frac{pi}{1+mbox{sgn}(x)}left(1-mbox{sgn}(y^2)right)-frac{pi}{4}left(2+mbox{sgn}(x)right)mbox{sgn}(y)$$
$$-mbox{sgn}(xy)*mbox{atan}left(frac{|x|-|y|}{|x|+|y|}right)$$
2)$$f(x,y)=pi-pi/2*(1+mbox{sgn}(x))(1-mbox{sgn}(y^2))-frac{pi}{4}(2+mbox{sgn}(x))mbox{sgn}(y)$$
$$-mbox{sgn}(xy)mbox{asin}left(frac{left|xright|-left|yright|}{sqrt{2*x^2+2*y^2}}right)$$
3)$$f(x,y)=pi-frac{pi}{2}(1+mbox{sgn}(x))(1-mbox{sgn}(y^2))-frac{pi}{4}(2+mbox{sgn}(x))mbox{sgn}(y)$$
$$-mbox{sgn}(left|xright|-left|yright|)mbox{sgn}(xy)mbox{acos}left(frac{left|xright|+left|yright|}{sqrt{2*x^2+2*y^2}}right)$$
Each of the formulas give the angle from $0$ to $2pi$ for any value of $x$ and $y$.
For $x=y=0$, the result is undefined.
New contributor
edited 22 hours ago
Alexander Gruber♦
20.1k24102171
20.1k24102171
New contributor
answered Nov 16 at 0:11
theodore panagos
211
211
New contributor
New contributor
Could you try to use MathJax to format the formula; as is this is hard to read. math.meta.stackexchange.com/questions/5020/…
– quid♦
2 days ago
add a comment |
Could you try to use MathJax to format the formula; as is this is hard to read. math.meta.stackexchange.com/questions/5020/…
– quid♦
2 days ago
Could you try to use MathJax to format the formula; as is this is hard to read. math.meta.stackexchange.com/questions/5020/…
– quid♦
2 days ago
Could you try to use MathJax to format the formula; as is this is hard to read. math.meta.stackexchange.com/questions/5020/…
– quid♦
2 days ago
add a comment |
up vote
0
down vote
In this recent answer, it is shown that
$$
theta=2arctanleft(vcenter{frac y{x+sqrt{x^2+y^2}}}right)
$$
This formula works for all $x,y$ except on the negative real axis, where $theta$ goes from just under $pi$ on top to just above $-pi$ underneath.
add a comment |
up vote
0
down vote
In this recent answer, it is shown that
$$
theta=2arctanleft(vcenter{frac y{x+sqrt{x^2+y^2}}}right)
$$
This formula works for all $x,y$ except on the negative real axis, where $theta$ goes from just under $pi$ on top to just above $-pi$ underneath.
add a comment |
up vote
0
down vote
up vote
0
down vote
In this recent answer, it is shown that
$$
theta=2arctanleft(vcenter{frac y{x+sqrt{x^2+y^2}}}right)
$$
This formula works for all $x,y$ except on the negative real axis, where $theta$ goes from just under $pi$ on top to just above $-pi$ underneath.
In this recent answer, it is shown that
$$
theta=2arctanleft(vcenter{frac y{x+sqrt{x^2+y^2}}}right)
$$
This formula works for all $x,y$ except on the negative real axis, where $theta$ goes from just under $pi$ on top to just above $-pi$ underneath.
answered 21 hours ago
robjohn♦
262k27300620
262k27300620
add a comment |
add a comment |
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f1327253%2fhow-do-we-find-out-angle-from-x-y-coordinates%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown