What is the Cartesian form of (4,5π2)?

1 Answer
Jul 17, 2016

The point is (0,4).

Explanation:

The standard conversion between polar and cartesian coordinates is:
x=rcos(θ)
y=rsin(θ)

The given coordinates are of the form (r,θ). And one will also note that:
5π2=π2+2π

Meaning that we can simply reduce the angle to π2 since we can always subtract full revolutions of the unit circle from angles in polar coordinates, so the result is:
x=4cos(π2)=0
y=4sin(π2)=4

The point, then, is (0,4)