Question

If $sec5A=cosec(A-30)$, then the value of $A$ is ___.

• A. 20
• B. 30
• C. 40
• D. 60

Answer 1

The correct option is A

20

$sec5A=cosec(A-30)$

$\Rightarrow cosec(90-5A)=cosec(A-30)$ ($\because sec\theta =cosec(90-\theta$)

$\Rightarrow 90-5A=A-30$

$\Rightarrow 6A=120$

$\Rightarrow A=20$