Question

For any angle $\theta$, state the value of : $si{n}^2\theta +co{s}^2\theta$.

• A. 7
• B. 1
• C. 2
• D. 5

Answer 1

The correct option is B 1

$si{n}^2\theta +co{s}^2\theta$
= $(\frac{P}{H}{)}^2+(\frac{B}{H}{)}^2$
= $\frac{P^2+B^2}{H^2}$ (Using Pythagoras Theorem)
= $\frac{H^2}{H^2}$
= $1$
For any $\theta$, $si{n}^2\theta +{\cos }^2\theta =1$