# Math Help - Polar and rectangular coordinates

1. ## Polar and rectangular coordinates

Any help is great. Steps or explanations are appreciated.

1. The polar coordinates (8.1, 5.2) converted to rectangular coordinates.
2. The rectangular coordinates (-.8, -2.1) converted to polar coordinates.
3. X and Y represent rectangular coordinates. Write each equation using polar coordinates.

$1. x^2+y^2=x$

$2. y^2=2x$

$3. 4x^2y=1$
4. The letters r and θ represent polar coordinates. Write each equation using rectangular coordinates.

$1. r=sin\theta+1$

$2. r=4$

2. Convert from one to the other using

$(x,y) = (r\cos(\theta),r\sin(\theta))$

where

$r = \sqrt{x^2+y^2}$

$
\theta = \tan^{-1}\left(\frac{y}{x}\right)
$