Question

Calcule o valor:
a) f(X)=x²+3x-10=0
b) f(X)=5x²+15x=0
c) f(X)= 2x²-18=0
d) f(X)=4x²-16=0

Answer 1

a) X²+3X-10=0
∆=B²-4.A.C
∆=3²-4.1.-10
∆=9+40
∆=49
√∆=7

X=-B+-√∆/2.A
X=-3+-7/2.1
X'= -3+7/2 = 2
X''= -3-7/2 = 5

b)∆=15²-4.5.0
∆=225
√∆=15

X=-15+-15/2.5
X'=-15+15/10 = 0
X''=-15-15/10 = -3

c)∆=0²-4.2.-18
∆=144
√∆= 12

X=-0+-12/2.2
X'=12/4 = 3
X''= -12/4 = -3

d)∆=0²-4.4.-16
∆=256
√∆=16

X=-0+-16/2.4
X'=16/8 = 2
X''=-16/8 = -2