Question

Jika f(x)=x2-4x+5, nilai f-1 (5)=...

Answer 1

Y = x²-4x+5
y-1 = x²-4x+5-1
y-1= x²-4x+4
y-1 = (x-2)(x-2)
y-1= (x-2)²
(y-1)^1/2 = [(x-2)²]^/12
x-2 = √(y-1)
x= 2+√(y-1)
f-¹(x) = 2+√(x-1)

f-1(5)= 2+√(5-1)
= 2+√(4)
= 2+2
=4