# Math Help - Cartesian Co-ordinates

1. ## Cartesian Co-ordinates

I'm really struggling with this question

2. Hey.

Cartesian Co-ords are the the one on the (x,y) graphs that you regularly work with.

Where polar Co-ords where each point is referenced from a fixed point and a angle (r, $\theta$)

So to convert between them there is a formula.
$x = r cos ( \theta )$
$y = r sin ( \theta )$
$r = \sqrt{y^2 + x^2}$

So with 2a
your answer would be (2cos( $\pi /3$),2sin ( $\pi /3$))

Then
2b
r = $\sqrt{2^2 + 2^2}$
$\theta$= tan $2/2$

I Used tan because I personally find it easier to visualise in my head. the co-ord is 2 along the x and 2 along the y direction.

( $\sqrt{8},45^\circ$)
Also you can simply convert the 45 degrees to radians if needed.

2 c,d I have never seen those before So I'll let someone more experienced to help there.