Question

if cos 2A is equal to sin bracket a minus 15 bracket then value of a is

Answer 1

Step-by-step explanation:

$\cos(2a) = \sin(a - 15)$

Divide both sides by cos(2a).

$1 = \frac{ \sin(a - 15) }{ \cos(2a) } \\ \tan( \frac{a - 15}{2a} ) = 1$

We know that,

$\tan(45) = 1$

Therefore,

$\frac{a - 15}{2a} = 45 \\ a - 15 = 90a \\ 89a = - 15 \\ a = \frac{ - 15}{89} = - 0.16$

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Hope it helps.....!