Convert
(-5, pi/4)
to rectangular coordinates.

A. (sqrt(2) / 2, sqrt(2) / 2)
B. (5 sqrt(3) / 2, 5/ 2)
C. (5 sqrt(2) / 2, 5 sqrt(2) / 2)
D. (-5 sqrt(2) / 2, -5 sqrt(2) / 2)

Question

Convert
(-5, pi/4) 
to rectangular coordinates.

A. (sqrt(2) / 2, sqrt(2) / 2)
B. (5 sqrt(3) / 2, 5/ 2)
C. (5 sqrt(2) / 2, 5 sqrt(2) / 2)
D. (-5 sqrt(2) / 2, -5 sqrt(2) / 2)

anonymous · Answer

I am thinking that it would be B. However I am having trouble understanding how to get my answer.

anonymous · Answer

$$x = rcos \theta$$$$y= rsin \theta$$

anonymous · Answer

$$x = (-5)\cos(\frac{ \pi }{ 4 })$$$$y = (-5)\sin(\frac{ \pi }{ 4 })$$

anonymous · Answer

I don't get any of the answers :(

anonymous · Answer

yes. last step is to use a unit circle to get sin (π/4) and cos (π/4)

anonymous · Answer

45?

anonymous · Answer

Oh sin and cos of 45?

anonymous · Answer

yes

anonymous · Answer

It would be A?

anonymous · Answer

D. 
A doesn't have -5 for r

anonymous · Answer

Oh you just said the answer didn't you

anonymous · Answer

yes r can be negative.
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