To find the inverse function of f(x) = 5x + 4 – 6 when x = 19, we will first simplify the function and then solve for its inverse.
First, let’s rewrite the function:
- f(x) = 5x – 2
Next, to find the inverse, we replace f(x) with y:
- y = 5x – 2
Now, we need to swap x and y:
- x = 5y – 2
Next, we will solve for y:
- Add 2 to both sides: x + 2 = 5y
- Now, divide both sides by 5: y = (x + 2) / 5
Thus, the inverse function is:
- f-1(x) = (x + 2) / 5
Finally, to find the value of the inverse function when x = 19, we substitute 19 into the inverse function:
- f-1(19) = (19 + 2) / 5 = 21 / 5 = 4.2
So, the value of the inverse function when x = 19 is 4.2.