SOLUTION: For the given functions f and g , find the indicated composition. f(x) = x2 - 2x - 5,g(x) = x2 + 2x + 1 (f∘g)(5)

Algebra ->  Functions -> SOLUTION: For the given functions f and g , find the indicated composition. f(x) = x2 - 2x - 5,g(x) = x2 + 2x + 1 (f∘g)(5)      Log On


   

Question 1178603: For the given functions f and g , find the indicated composition.
f(x) = x2 - 2x - 5,g(x) = x2 + 2x + 1
(f∘g)(5)
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

f%28x%29+=+x%5E2+-+2x+-+5
g%28x%29+=+x%5E2+%2B+2x+%2B+1

(f∘g)(5)
first find
(f∘g)(x)
(f∘g)(x)=f%28g%28x%29%29
(f∘g)(x)=f%28x%5E2+%2B+2x+%2B+1%29
(f∘g)(x)=%28x%5E2+%2B+2x+%2B+1%29%5E2-2%28x%5E2+%2B+2x+%2B+1%29-5
(f∘g)(x)=x%5E4+%2B+4x%5E3+%2B+4x%5E2+-6

now find
(f∘g)(5)
(f∘g)(5)=5%5E4+%2B+4%2A5%5E3+%2B+4%2A5%5E2+-6
(f∘g)(5)=1219