Integrated Math 1 / Unit 1: Quantities and Expressions
1.6 Exponent Rules
Notes
An exponent tells how many times a base is multiplied by itself: $x^4 = x \cdot x \cdot x \cdot x$.
- Product rule: $x^a \cdot x^b = x^{a+b}$. Quotient rule: $\displaystyle \frac{x^a}{x^b} = x^{a-b}$.
- Power rule: $(x^a)^b = x^{ab}$ and $(xy)^a = x^a y^a$.
- Zero exponent: $x^0 = 1$ for $x \neq 0$. Negative exponent: $\displaystyle x^{-n} = \frac{1}{x^n}$.
- Example: $(3a^2)^2 = 9a^4$. Coefficients are squared too.
Practice
Simplify $x^3 \cdot x^4$.
When multiplying powers with the same base, add the exponents.
Simplify $(2a^3)^2$.
Square the 2 to get 4 and multiply the exponents: $3 \cdot 2 = 6$.
What is $5^0 + 2^{-3}$?
$5^0 = 1$ and $\displaystyle 2^{-3} = \frac{1}{8}$, so the sum is $\displaystyle \frac{9}{8}$.
Ready for more? Take the Unit 1 test.