Question

If $\sec 2A=\csc (A-{42}^{\circ })$ where $2A$ is acute angle then value of $A$ is

• A. ${44}^{\circ }$
• B. ${22}^{\circ }$
• C. ${21}^{\circ }$
• D. ${66}^{\circ }$

Answer 1

The correct option is A ${44}^{\circ }$

$\sec 2A=\csc (A-{42}^{\circ })$
$\csc (90-2A)=\csc (A-{42}^{\circ })$
$90-2A=A-42$
$3A=132$
$A={44}^{\circ }$