### Home > PC3 > Chapter 11 > Lesson 11.2.4 > Problem 11-131

11-131.

COMPLEX NUMBERS: STANDARD

Rewrite the following complex number in polar form:

Graph the point

. 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.Rewrite the following complex number in standard form:

Use the half-angle identity for cosine or a calculator to compute

.