COMPLEX NUMBERS: STANDARD $⇔$ POLAR

1. Rewrite the following complex number in polar form: $−2 − 9i$

   Hint (a):

   Graph the point $(−2, −9)$. Then create a right triangle with the x-axis.
   The hypotenuse of the triangle is the radius. Use the tangent ratio to determine the angle.

2. Rewrite the following complex number in standard form: $9(\cos(\frac { 5 \pi } { 8 }) + i \sin(\frac { 5 \pi } { 8 }))$

   Hint (b):

   Use the half-angle identity for cosine or a calculator to compute $\cos(5π/8)$.