Q. (7pts) Let f(x)=2x+x. Use the theorem on derivatives of inverses to find (f−1)′(11).
Find Derivative of f(x): First, we need to find the derivative of f(x), which is f′(x).f′(x)=dxd[2x+x]
Calculate f′(x): Using the power rule and the fact that the derivative of x is 1, we get:f′(x)=2x⋅ln(2)+1
Apply Derivative of Inverses Theorem: Now, we use the theorem on derivatives of inverses which states that (f−1)′(y)=f′(f−1(y))1. We need to find (f−1)′(11), so we need to calculate f′(f−1(11)).
Find x for f(x)=11: We need to find the x-value such that f(x)=11. This means solving 2x+x=11 for x.
Approximate x Value: This equation isn't easy to solve algebraically, so we might need to use numerical methods or graphing to approximate the solution.Let's say we found that x≈3 (this is an approximation for the sake of the example).