Question 651809
How would you find the inverse of x^2 − 4x − 21 on the restricted domain [2, infinity)?
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I'm not all sure about this problem, but let me give it a try:
Given function is a parabola so it is not a one-to-one function and therefore, cannot have on inverse. However, restricting the domain to [2,∞) is using only the right half of the parabola which now becomes a one-to-one function.
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Finding the inverse of a function is like solving for x in terms of y.
My guess then the inverse would be x=y^2-4y-21, with the domain and range in reverse to that of the original function, that is, from [2,∞) and [25, ∞) to [25,∞) and [2,∞)
This means for an inverse, only the top half of the parabola can be used.