Question

Cum as putea rezolva?

Answer 1

cos(2x)=cos(x)²-sin(x)²  putem asta desface in 2 termeni

=[cos(x)²-sin(x)²] / [sin(x)²·cos(x)²] =

1/sin(x)² - 1/cos(x)²=∫1/sin²(x)dx - ∫1/cos²(x)dx=

-ctg(x)-tg(x) I(π/2,0)= -ctg(π/2)-tg(π/2)+ctg(0)+tg(0)=

0+0=0                                                                 vrode asa