how do i solve this

Question

if f(x)=2x-4 and g(x)=x² find f(1)+g(2)

Answer 1

f(1) = 2(1)-4 =2-4=-2

g(2) = 2^2 =4

f(1)+g(2) =-2 +4 = 2

Answer 2

Hi Kaylin,

I'm thinking that you might need help understanding functional notation.

In other words, what does f(x) mean?

The f(x) notation is trying to tell us 3 things.

1. The name of the function is "f".

2. The input to the function is x.

3. The whole thing "f(x)" is the output. (or another name for "y")

In this problem, we're told that f(x) = 2x - 4

The "2x - 4" is the number-crunching instructions.

It tells us what "f" DOES with the input.

In this problem, "f" takes the input, multiplies it by 2 and then, subtracts 4.

f(1) is asking us to find the output of "f" when the input is 1.

Just substitute 1 for x, f(1) = 2(1) - 4.

Therefore, f(1) = -2

REALLY, IT'S THAT EASY!!

Let's finish the problem.

g(x) = x² means "g" squares its input.

Therefore g(2) = 2² = 4.

Finally, f(1) + g(2) = -2 + 4 = 2.

I hope this helps.