Question

$\sin \theta \cos (90-\theta )+\cos \theta \sin (90-\theta )=$

• A. $0$
• B. $1$
• C. $2$
• D. $\frac{3}{2}$

Answer 1

Answer: (B)

$1$

Given,

$\sin \theta \cos \left({90}^o-\theta \right)+\cos \theta \sin \left({90}^o-\theta \right)$

$=\sin \theta \sin \theta +\cos \theta \cos \theta$

$={\sin }^2\theta +{\cos }^2\theta$

$=1$

1 is the answer