Question

DADA A FUNÇÃO F DE LEI F(X) = x2 + 3x - 10, CALCULE:

A) f(0)
B) f(-1)
C) x para f(x) = 0
D) x para f(x) = 0
E) x para f(x) = -6

Answer 1

f(x)=x²+3x-10

a)f(0)=0²+3.0-10= 0+0-10= -10

b)f(-1)=(-1)²+3.(-1)-10= 1 -3 -10= -2-10= -12

c)f(2)=2²+3.2-10= 4+6-10=10-10=0

d)0=x²+3x-10
∆=3²-4.1.(-10)
∆=9+40
∆=49
x= -3±√49/2.1
x= -3±7/2
x1= -3+7/2= 4/2=2
x2= -3-7/2= -10/2= -5

e) -6=x²+3x-10
x²+3x-10+6=0
x²+3x-4=0
∆= 3²-4.1.(-4)
∆=9+16
∆=25
x= -3±√25/2.1
x= -3±5/2
x1= -3+5/2=2/2=1
x2= -3-5/2=-8/2=-4