Topic: Inverse tangent

Hi smile
I have 2 questions.
Firstly:
How do i make inverse tangent, if I fx wants to write tan^-1(x/y)
Secondly:
Is it possible to sketch the following relation (polar coordinates)
2<r<=5, (3pi)/4<Ө<(5pi)/4?
Hope you can help smile
//Trixap

Re: Inverse tangent

trixap wrote:

How do i make inverse tangent, if I fx wants to write tan^-1(x/y)

Try using the atan function.

trixap wrote:

Is it possible to sketch the following relation (polar coordinates)
2<r<=5, (3pi)/4<Ө<(5pi)/4?

Graph does not support polar inequalities, but you can convert it into Cartesian coordinates:
2 < sqrt(x^2+y^2) <= 5 and 3pi/4 < angle(x,y) < 5pi/4

You can create the angle function as a custom function:
angle(x,y)=if(x<0, atan(y/x)+pi, atan(y/x))

I have attached a file that shows this.

Post's attachments

Attachment icon Polar inequality.grf 733 b, 638 downloads since 2010-08-31 

Re: Inverse tangent

Thank you helped a lot smile