SOLUTION: F(x) =x^2+2x+4 ; g(x)=v(9-x) (When I do v() that is a square root symbol) Find each of the following if it exists: My question is (fg)(-7) (-7^2+(2)(-7)+4)(v(9-(-7)) (-4

Question 764988: F(x) =x^2+2x+4 ; g(x)=v(9-x) (When I do v() that is a square root symbol)
Find each of the following if it exists:
My question is (fg)(-7)
(-7^2+(2)(-7)+4)(v(9-(-7))
(-49-14+4)(v(16))
(-59)(4)
-236
I'm wondering if I figured this out correctly. The minus negative 7 in the square root is throwing me off I dont understand if i should add the 7 because there are two negatives or if I should subtract a negative 7 and also the negative 7 squared it throwing me off I'm confused about how I should count the negatives. Should I count it as -7^2 or (-7)^2? Thank you very much for your help.
Found 2 solutions by josgarithmetic, stanbon:
Answer by josgarithmetic(39617) (Show Source): You can put this solution on YOUR website!
"F(x) =x^2+2x+4 ; g(x)=v(9-x) (When I do v() that is a square root symbol)"
You mean this for the second function: g(x)=sqrt(9-x) or

You ask for help with the composition F of g, evaluated at x=-7.
First, form the composition:

Now just let x=-7 and see what is the evaluation.

Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
F(x) =x^2+2x+4 ; g(x)=sqrt(9-x)
Find each of the following if it exists:
My question is (fg)(-7)
--------
That is either fog(-7) or it is f*g(-7)
----
If it is fog(-7) you get:
f[g(-7)] = f[sqrt(16)] = f(4) = 4^2+2*4+4 = 28
------
If it is f*g(-7) = f*4 = 4x^2+8x+16
=====================================
Cheers,
Stan H.
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