Question

Find the value of x if cos2x =cos60×cos30+sin60×sin30

Answer 1

Answer:

Step-by-step explanation:

This may help you guys.....

Answer 2

Answer:

Value of x = 15°

Step-by-step explanation:

$cos2x=cos60cos30+sin60sin30$

$\implies cos2x=cos(60-30)$

/* we know that

$\boxed {cosAcosB+sinAsinB\\=cos(A-B)}$ */

$\implies cos2x = cos30\degree$

$\implies 2x = 30\degree$

$\implies x = \frac{30}{2}$

$\implies x = 15\degree$

Therefore,

Value of x = 15°

•••♪