To solve this problem you must apply the proccedure shown below:
1. You have the following parametric equations given in the problem above:
x=4cosθ
y=4sinθ
2. Therefore, you have:
x=rcosθ
y=rsinθ
x=4cosθ
rcosθ=4cosθ
3. Solve for r:
r=4cosθ/cosθ
r=4
Therefore, the answer is: r=4 and assuming that θ goes from 0 to 2π.
