Given f(x) = 2x+4, you found the inverse of this function is f^−1(x) = mx + b
2 answers
swap x and y ... x = 2 y + 4 ... solve for y ... y = 1/2 x - 2
Mark f(x) as y
y = 2 x + 4
Replace all x with y and y with x
x = 2 y + 4
Subtract 4 to both sudes
x - 4 = 2 y
2 y = x - 4
Divide both sides by 2
y = x / 2 - 4 / 2
y = 1 / 2 x - 2
f ⁻¹ (x) = 1 / 2 x - 2
y = 2 x + 4
Replace all x with y and y with x
x = 2 y + 4
Subtract 4 to both sudes
x - 4 = 2 y
2 y = x - 4
Divide both sides by 2
y = x / 2 - 4 / 2
y = 1 / 2 x - 2
f ⁻¹ (x) = 1 / 2 x - 2