If f(x)=x2+4x−5 and g(x)=2x−1, then (g∘f)(x) is ...
Explanation
We want to find the composite function (g∘f)(x).
Understanding Function Composition
The composite function (g∘f)(x) is defined as:
(g∘f)(x)=g(f(x))
This means we will substitute the entire function f(x) into the variable x in the function g(x).
Function Substitution
Given:
- f(x)=x2+4x−5
- g(x)=2x−1
We substitute f(x) into g(x):
(g∘f)(x)=g(x2+4x−5)
Since g(x)=2x−1, we replace every x in g(x) with (x2+4x−5):
(g∘f)(x)=2(x2+4x−5)−1
Simplifying the Result
Now we distribute the multiplication and simplify:
(g∘f)(x)=(2⋅x2)+(2⋅4x)−(2⋅5)−1
(g∘f)(x)=2x2+8x−10−1
(g∘f)(x)=2x2+8x−11
Conclusion
Thus, the composite function is 2x2+8x−11.