Question

ma puteti ajuta va rog frumos...​

Answer 1

2. f(x) <\ 2

x^2- x -2 <\0

delta= 1+8= 9

x1= (1+3)/2= 2

x2= (1-3)/2 = -1

deci x apartine [-1, 2]

6. sin2x = 2sinx × cosx

Putem folosi formula (a+b)^2 = a^2 +2ab+ b^2 pt a le aplica pe amandoua

sin^2 x + cos^2x= 1^2= 1

Rezolvare: (sinx + cosx)^2= sin^2 x + 2sinxcosx + cos^2x

1= 1+2sinxcosx

2sinxcosx = 0

sin2x=0