Question

Consider this equation. cos(theta) = (-2√5)/5. If theta is an angle in quadrant II, what is the value of sin(theta)? NO LINKS!!!​

Answer 1

Explanation:

Answer 2

• In second quadrant sin and cosec are positive

`\\ \tt\hookrightarrow sin^2\theta=1-cos^2\theta`

`\\ \tt\hookrightarrow sin^2\theta=1-((-2√(5))/(5))^2`

`\\ \tt\hookrightarrow sin^2\theta=1-(20)/(25)`

`\\ \tt\hookrightarrow sin^2\theta=(5)/(25)`

`\\ \tt\hookrightarrow sin\theta=(√(5))/(5)`

`\\ \tt\hookrightarrow sin\theta=(1)/(√(5))`