Given f(x)=2x−3, g(x)=x2+4x−1, and (g∘f)(x)=ax2+bx+c, then the value of a+b+c=
Explanation
We are given the functions f(x)=2x−3 and g(x)=x2+4x−1. We need to find the value of a+b+c from the composite function (g∘f)(x)=ax2+bx+c.
First, let's determine the composite function (g∘f)(x):
(g∘f)(x)=g(f(x))
=g(2x−3)
=(2x−3)2+4(2x−3)−1
Expand the squared term and the product:
=(4x2−12x+9)+(8x−12)−1
Combine like terms:
=4x2−12x+8x+9−12−1
=4x2−4x−4
From the form ax2+bx+c, we obtain:
a=4,b=−4,c=−4
So the value of a+b+c is:
a+b+c=4+(−4)+(−4)
=4−4−4
=−4
Thus, the value of a+b+c=−4.