Question

What is the inverse for the function? y= 2x + 3

Answer 1

y = 2x + 3

Let y = f(x), solving for the inverse function is solving for x

y = 2x + 3

2x + 3 = y

2x = y - 3

x = (y - 3)/2

Recall that y = f(x), that implies that x = f⁻¹( y)

x = (y - 3)/2, substitute x = f⁻¹( y)

f⁻¹( y) = (y - 3)/2

if f⁻¹( y) = (y - 3)/2, then: Replace the y with x.

f⁻¹(x) = (x - 3)/2

Answer 2

for
y
y
.
f
−
1
(
x
)
=
−
3
2
+
x
2