SOLUTION: f(x) is a function such that f(1)=2, f(4)=3, f(7)=4, f^-1(x) is the inverse of f(x),what is f^-1(f^-1(3))? Thank you.

Question 919877: f(x) is a function such that f(1)=2, f(4)=3, f(7)=4, f^-1(x) is the inverse of f(x),what is f^-1(f^-1(3))? Thank you.
Found 2 solutions by MathLover1, josgarithmetic:
Answer by MathLover1(20850) (Show Source): You can put this solution on YOUR website!

=> means if then ;it's point (,)
=> means if then ;it's point (,)
=> means if then ;it's point (,)
use these points to find what is equal to

Solved by pluggable solver: Find the equation of line going through points

hahaWe are trying to find equation of form y=ax+b, where a is slope, and b is intercept, which passes through points (x1, y1) = (1, 2) and (x2, y2) = (7, 4).
Slope a is .
Intercept is found from equation , or . From that,
intercept b is , or .

y=(0.333333333333333)x + (1.66666666666667)

Your graph:

so, or

then inverse will be:
...swap and

or

what is : first find and plug it in

Answer by josgarithmetic(39618) (Show Source): You can put this solution on YOUR website!
f^-1(2)=1, f^-1(3)=4, f^-1(4)=7.

Start with the inside of your unknown expression and work outward.

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