Question

Which rectangular equation is equivalent to the polar equation r cos(theta)=-2?

Answer 1

hint , you can choose from the following polar/rectangular conversion equations:
$$\Large{
x = r \cos \theta\\
y= r \sin \theta\\
r = \sqrt{x^2+y^2 }
\\ \theta = \arcsin(y/ x)
}
$$

Answer 2

@perl

r cosθ = −2

I think the answer is:

B. x = −2