Question

Complex number question:
Express 5-2i in polar form. Express your answer in radians to the nearest hundredth.
r=sqrt(5^2+(-2)^2)
=sqrt(25+4)
=sqrt(29)
theta=arctan -2/5
=-0.38
question: is this the proper theta value or do I need to find the reference angle?

Answer 1

So in other words I'm not sure if it should be sqrt(29)(cos(-0.38)+i sin(-0.38)) or
sqrt(29)(cos(5.9)+i sin(5.9))

Answer 2

they are equivalent ... i guess proper form would use the positive angle

Answer 3

thanks! just wanted to make sure I was using the correct one :)

Answer 4

so like 339 degree angle?

Answer 5

then convert that to radians and use it in the equation?

Answer 6

No just set your calculator to radians when you do arctan -2/5 and then you don't have to convert