SOLUTION: calculate the indicated valu: f(x) = 13x - 10 g(x) = -12x^3 + 11x^2 - 12x - 11 find f(g(3)) I asked a question about a similar question and took what I learned to come up wi

Algebra ->  Functions -> SOLUTION: calculate the indicated valu: f(x) = 13x - 10 g(x) = -12x^3 + 11x^2 - 12x - 11 find f(g(3)) I asked a question about a similar question and took what I learned to come up wi      Log On


   

Question 83997: calculate the indicated valu:
f(x) = 13x - 10
g(x) = -12x^3 + 11x^2 - 12x - 11
find f(g(3))
I asked a question about a similar question and took what I learned to come up with the answer of f(g(3)=3,526, I just wanted to double check to see if this is correct, thank you!
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Lets first find g%283%29 which is the inner function

g%283%29=-12x%5E3+%2B+11x%5E2+-+12x+-+11 Start with the given equation

g%283%29=-12%283%29%5E3+%2B+11%283%29%5E2-12%283%29+-+11 Plug in x=3

g%283%29=-12%2A27%2B+11%2A9-12%2A3+-+11 Square and cube 3

g%283%29=-324+%2B+99-36+-11 Multiply

g%283%29=-272 Combine like terms

Since g%283%29=-272, f%28g%283%29%29=f%28-272%29

So lets find f%28-272%29

f%28-272%29=13x+-+10 Start with the given equation

f%28-272%29=13%28-272%29+-+10 Plug in x=-272

f%28-272%29=-3536+-+10 Multiply

g%28-272%29=-3546 Combine like terms

So f%28g%283%29%29=-3546