Posted by Jo on Sunday, March 6, 2011 at 12:48pm.
determine if the given function is onetoone. if it is, find the inverse.
f(x) = 8x  4
A) f1(x) = x+4 / 8
B) f1(x) = x4 / 8
C) Not onetoone
D) f1(x) = x/8 + 4

Math  MathMate, Sunday, March 6, 2011 at 1:01pm
All functions that are strictly increasing or decreasing in its domain are onetoone.
Since the given function has a constant positive slope, it is strictly increasing over ℝ, so it is onetoone.
The inverse can be found as follows:
1. interchange x and y to get
from f(x) = y = 8x  4
to
x=8y4
2. Solve for y in terms of x:
8y=x+4
y=(x+4)/8
Now there is sufficient information to find the correct answer.