Question

(sinx+cosx)^2+(sinx-cosx)^2=2​

Answer 1

Răspuns:

$(sinx+cosx)^2+(sinx-cosx)^2=2$

$sin^2x+cos^2x+2sinx*cosx+sin^2x+cos^2x-2sinx*cosx=2$

$2(sin^2x+cos^2x)=2$

Dupa formula fundamentala a trigonometriei $sin^2x+cos^2x=1$

$=> 2*1=2$ "Adevarat"