### Home > PC3 > Chapter 9 > Lesson 9.2.2 > Problem9-119

9-119.

Suppose $\cos(x)=-\frac { 5 } { 7 }$ where $π < x <\frac { 3 \pi } { 2 }$.

1. Determine the exact values of the five other trigonometric ratios. Rationalize the denominator if necessary.

Sketch a diagram of this situation.

Now calculate the length of the missing leg.
Then you should be able to state the all of the trigonometric ratios.

2. Calculate the exact values of $\sin(2x)$ and $\cos(2x)$.

$\sin(2x) = 2\sin(x)\cos(x)\\ \cos(2x) = \cos2(x) − \sin2(x)$