4-2

I’m posting this super early, but it’s because I won’t be home till late Sunday night! Anyways, Section 4-2 dealt with notation. There are four formulas to find notation: sum, difference, product, and quotient of functions.
1. Sum of f and g: (f+g)(x) = f(x) + g(x)
2. Difference of f and g: (f-g)(x) = f(x) – g(x)
3. Product of f and g: (f x g)(x) = f(x) x g(x)
4. Quotient of f and g: (f/g)(x) = f(x)/g(x), provided g(x) not equaled to 0
*f(x) is a notation!

EXAMPLE 1: f(x) = 2x + 1 and g(x) = 2 – x Find the sum and difference notations.
A). (f+g)(x) = (2x+1) + (2-x)
= x + 3
B). (f-g)(x) = (2x+1) – (2-x)
= 3x -1

EXAMPLE 2: If you have f(#), f(y), or f(i^2), the notations means to plug what is in the parenthesis into the equation instead of x. Knowing this, solve (f+g)(3) using Example 1’s f(x) and g(x).
A). (f+g)(3) = (2x+1) + (2-x)
= x + 3
B). Plug in 3 into the above answer.
= 3 + 3
C). Your answer is 6.