Hello, Leo!

Sine is positive in Quadrants 1 and 2.Given that: . and that and are in the same quadrant,

without finding the angles and , find the value of

Cosine is negative in Quadrants 2 and 3.

. . Hence, angles and are in Quadrant 2.

We have: . in Quadrant 2.

Since , we have: .

. .

Since is in Quadrant 2: .

We have: . in Quadrant 2.

Since , we have: .

. .

Since is in Quadrant 2: .

We know that: .

Substitute: .