NMTC Inter Level Problem 3 + Figure-It-Out Function! - Part 5: Inverses

We have: 1. $3f(\frac{1}{4}) - 2f(4) = \frac{1}{4}$ and 2. $3f(4) - 2f(\frac{1}{4}) = 4$ . Adding the two equations we get 3. $f(\frac{1}{4}) + f(4) = \frac{17}{4}$ . Add 1 to 3 and get: 4. $4f(\frac{1}{4}) - f(4) = \frac{17}{4} + \frac{1}{4}$ Add 3 to 4: $5f(\frac{1}{4}) = \frac{17}{2} + \frac{1}{4} \to f(\frac{1}{4}) = \frac{7}{4}$ Sub this into one of the equations and solve for $f(4)$ and obtain $f(4) = \frac{5}{2}$

replace x by 1/x then there will two equation and solve for f(x)....and put the value of x equal to 4 and you will get answer 2·5