Question

Calculati:cos(2x+2x)​

Answer 1

Răspuns:

$cos(4x)$ In functie de cos

$cos(4x)$

$cos(2*2x)$

$2cos^2(2x)-1$

$2(cos(2*x))^2-1$

$2(2cos^2x-1)^2-1$

$2(4cos^4x-4cos^2x+1)-1$

$8cos^4x-8cos^2x+2-1$

$8cos^4x-8cos^2x+1$