Question

Calcule o valor da função f(×)=ײ-5×+2 para:

A) x = - 4
B) x = - 1
C) x = 3/2
D) x = √2

Answer 1

$f(-4)=(-4)^2-5.(-4)+2=16+20+2=38\\ \\ f(-1)=(-1)^2-5.(-1)+2=1+5+2=8\\ \\ f(\frac{3}{2})=(\frac{3}{2})^2-5.(\frac{3}{2})+2=\frac{9}{4}-\frac{15}{2}+2=\frac{9-30+8}{4}=-\frac{13}{4}\\ \\ f(\sqrt2)=(\sqrt2)^2-5.\sqrt2+2=4-5\sqrt2+2=6+\sqrt2$