give a polar equation for the curve whose graph is a vertical line that passes 3 units?

Question

to the right of the origin

possible answers:

r=3
rcos theta=3
y=3
sin theta=3

Answer 1

r=a Sec(theta) will graph the line x=a, so you want r= 3 sec(theta)...

to do the same with y=3, graph 3 cosec(theta)...

enjoy

Answer 2

The Cartesian equation of the line is x = 3.

Remember the identity.
x = rcosθ

r = x/cosθ

Plug in the value for x.

r = 3/cosθ

To put the answer in your form multiply by cosθ.

rcosθ = 3