Basic Operations
Multiplying Functions
To multiply functions, replace the equivalent expressions and then multiply using the Distributive Property. Remember, the Product Rule of Exponents states that when multiplying terms with the same base, add the exponents.
For example: xm ? xn = x(m+n).
Example Given f(x) = 3x– 5 and g(x) = 6x + 5, find f(x) · g(x).
Step 1. Replace f(x) and g(x) with their equivalent expressions.
f(x) · g(x)
(3x – 5) · (6x + 5)
Step 2. Multiply.
(3x)(6x) + (3x)(5) + (-5)(6x) + (-5)(5)
18x2 + 15x – 30x – 25
18x2 – 15x – 25