Which is the polar form of the parametric equations x=5cos(theta) and y=5sin(theta) ? a. r= 5(theta) b. r= 5 c. r= 25 cos (theta) sin (theta) d. r= 25cos^2 (theta) + 25sin^2 (theta)

The polar coordinates are (r,φ), where r= and cosφ=, sinφ=.
So, when we are counting r, we obtain that r==
That's why the polar form of the parametric equations is r=5 (the circle of radius 5) and the right answer is B.