change the polar coordinates (4root2,3pi/4) to rectangular coordinates.?

Question

possible answers:
(-4,0)
(-4,4)
(0,4)
(4,4)

Answer 1

x = r cosΘ
y = r sinΘ

just plug them.

d:

Answer 2

x coordinate 4sqrt(2) * cos (3pi/4) =
4sqrt(2) * cos (pi - pi/4) = 4sqrt(2) * -sqrt(2)/2 = -4

y coordinate 4sqrt(2) * sin (3pi/4) =
4sqrt(2) * sin (pi - pi/4) = 4sqrt(2) * sqrt(2)/2 = 4

The answer is (-4,4)