### Home > PC3 > Chapter 11 > Lesson 11.2.3 > Problem11-115

11-115.

Write the rectangular form of each complex number. Use exact values.

1. $z = 6(\cos(\frac { 5 \pi } { 6 })+ i \sin (\frac { 5 \pi } { 6 }))$

Substitute the exact values for sine and cosine of $5π/6$.

$z=6\left( -\frac{\sqrt{3}}{2}+\frac{1}{2}i \right)$

Distribute.

1. $z = 7(\cos(\frac { 3 \pi } { 2 })+ i \sin(\frac { 3 \pi } { 2 }))$