Question

considerand functia f:R->R,f(x)=ax+3a-2,a€N* ce verifica relatia f(a)=8,valoarea parlamentului a este egala cu​

Answer 1

f(a)=8

f(a)=$a^2+3a-2$

$a^2+3a-2=8\\a^2+3a-2-8=0\\a^2+3a-10=0$

Δ=$b^2-4ac$

Δ=9+40

Δ=49

$a_{1/2}=\frac{-3+-7}{2} = > \ a_1=2;a_2=-5$