Function plug-ins: Given F(x)=x^2+2x+7, g(x)= x+3, find (f+g)(x), (g*h)(x)

[matthewbareno]

Given that:
F(x)= x^2+2x+7
g(x)= x+3

What is (f+g) (x) ?
And for that matter, (g*h) (x) ?

 

[tkhunny]

Let's first assume that F(x) is the same as f(x). Normally, this is exceptionally bad form. Don't change letters to mean the same thing.

What we have here is just a notational convention.

(f+g)(x) = f(x) + g(x) -- Combine like terms and you are done.

(f*g)(x) is the same, just with multiplication.

The funny one is usually \(\displaystyle (f \circ g) = f(g(x))\).

 

[stapel]

Given that:
F(x)= x^2+2x+7
g(x)= x+3

What is (f+g) (x) ?
And for that matter, (g*h) (x) ?

To learn how to apply "operations" to functions, try here.