Question

If sin 6A = cos 9A, then m/A is equal 1) 6 2) 36 3) 45 4) 1 1/2

Answer 1

Original expresion

$\sin (6A)=\cos (9A)$

Let's use the following relationship to determine the answer

$\sin 6A=\cos (90-6A)$

Now in the original expression

$\begin{gathered} \cos (90-6A)=\cos 9A \\ 90-6A=9A \\ 90=6A+9A \\ 15A=90 \\ A=\frac{90}{15} \\ A=6 \end{gathered}$

The answer would be A = 6