Question

2cos 5α multiply cos 2α =

Answer 1

solution: -

$\implies \: 2 \cos5 \alpha . \cos2 \alpha$

we know that formula of

$\implies \pink{ 2\cos a. \cos \: b = \cos(a - b) + \cos(a </u><u>+</u><u> b) }$

$\implies \: \cos( 5\alpha - 2\alpha ) + \cos(5 \alpha + 2\alpha ) \\ \\ \implies \: \cos 3\alpha + \cos7 \alpha$

________________________

thanks

Answer 2

Answer:

refer the attachment plz mark me as brainlist