Question

If sin ${50}^0=0.766,$ then value of sec${40}^0$ is

• A. $1$
• B. $0.766$
• C. $\frac{1}{0.766}$
• D. $0$

Answer 1

The correct option is C $\frac{1}{0.766}$

$\sin {50}^{\circ }=0.766\Rightarrow \sin ({90}^{\circ }-{40}^{\circ })=0.766\Rightarrow \cos {40}^{\circ }=0.766\Rightarrow \sec {40}^{\circ }=\frac{1}{0.766}$