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Loppyfoot
Sep14-09, 06:24 PM
1. The problem statement, all variables and given/known data
If f(x) = x3+3x2+4x+5 and g(x)=5, then g(f(x)) = ?


2. Relevant equations



3. The attempt at a solution
I don't know if I am correct.
g(f(x)) =
g(x3+3x2+4x+5)= 225?

I plugged 5 into the equation. Am I right?

mathie.girl
Sep14-09, 06:47 PM
1. The problem statement, all variables and given/known data
If f(x) = x3+3x2+4x+5 and g(x)=5, then g(f(x)) = ?


2. Relevant equations



3. The attempt at a solution
I don't know if I am correct.
g(f(x)) =
g(x3+3x2+4x+5)= 225?

I plugged 5 into the equation. Am I right?

If you plugged 5 into f(x), then you calculated f(5) = f(g(x)), since g(x) = 5. You want to find g(f(x)), which means plug f(x) into g(x).

If you're having trouble, maybe ask yourself, what's g(1), g(10), g(1000)? Once you see a pattern, then g(f(x)) shouldn't be much harder.

Loppyfoot
Sep14-09, 07:06 PM
How do I plug a function into an integer? Would g(f(x)) just be 5?

Office_Shredder
Sep14-09, 07:32 PM
g(x) isn't an integer. It's called a constant function. And yep, g(f(x))=5.