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)

Which is the polar form of the parametric equations x=4t and y=t^2?
a. r= 16 tan (theta) sec (theta)*****
b. r= 16 tan^2 (theta)
c. r= 16 sec^2 (theta)
d. r= 16 sec (theta)

A bowling ball is rolled down the alley with a constant velocity of 1.5m/sec. at an angle of 87 degrees to the starting line. The position of the person throwing the bowling ball can be represented by the point (0,0). Where is the ball after 7 seconds?
a. (0.5,10.5)
b. (0.1,1.5)
c. (10.5,10.5)*****
d. (29,200)

2 answers

There are 4 main conversion relations that you need
r^2 = x^2 + y^2
x = rcosØ
y = rsinØ
tanØ = y/x

Your given parametric equations represent a circle with radius 5
http://www.wolframalpha.com/input/?i=plot+x%3D5cos(theta),+y%3D5sin(theta)
r = 5 would do the same

#2. convert to Cartesian first , then to polar
Reiny is being rude as hell