To find the inverse of the function given by y = 2x² + 2, we need to follow these steps:
- First, replace y with x:
- x = 2y² + 2
- Now, isolate y²:
Subtract 2 from both sides:
x – 2 = 2y²
Now, divide by 2:
y² = (x – 2) / 2
y = ±√((x – 2) / 2)
However, we need to determine which part of the square root to take. The original function y = 2x² + 2 is a parabola that opens upwards and has its vertex at (0, 2). To keep the inverse a function, we only consider the positive square root:
y = √((x – 2) / 2)
So, the inverse function is:
f-1(x) = √((x – 2) / 2)
This inverse will only be valid for values of x that are greater than or equal to 2, as those are the values that correspond to y in the original function.