Question

write the polar equation in rectangular form
r=-12 cos theta

Answer 1

hint multiply r on both sides

Answer 2

so -12 times r?

Answer 3

\[r^2=-12 r \cos(\theta)\]

Answer 4

I bet you know what rcos(theta) equals and r^2 equals in terms of x and y.

Answer 5

im lost sorry

Answer 6

\[x^2+y^2=r^2 \\ rcos(\theta)=x \\ rsin(\theta)=y\]

Answer 7

\[\tan(\theta)=\frac{y}{x}\]

Answer 8

you only need two of the equations I listed

Answer 9

for this particular equation

Answer 10

so this is the answer?

Answer 11

what is?

Answer 12

tan(0)=x/y

Answer 13

how did you get

Answer 14

\[r^2=-12 r \cos(\theta)\]
do you see the r^2 and the rcos(theta)?

Answer 15

tan(theta)

Answer 16

I gave you two equations above that told you what those were in terms of x and y

Answer 17

do you want to try again to apply those equations I gave to your equation

Answer 18

\[r=-12 \cos(\theta) \\ r \cdot r =r \cdot (-12 \cos(\theta)) \\ r^2=-12 r \cos(\theta) \\ \text{ replace } r^2 \text{ with } x^2+y^2 \\ \text{ replace } r \cos(\theta) \text{ with } x \\ \text{ this is \because } r^2=x^2+y^2 \text{ and } r \cos(\theta)=x \]