Transcript Algebra Expressions and Real Numbers
Section P3 Radicals and Rational Exponents
Square Roots
Definition of the Principal Square Root If a is a nonnegative real number, the nonnegative number b 81 9 9 64 3 8 7
Examples Evaluate
36
16
121
Simplifying Expressions of the Form
a
2
The Product Rule for Square Roots
A square root is simplified when its radicand has no factors other than 1 that are perfect squares.
Examples Simplify:
4900
Examples Simplify:
4
x
63
x
The Quotient Rule for Square Roots
Examples Simplify:
9 49 54
x
3 2
x
Adding and Subtracting Square Roots
Two or more square roots can be combined using the distributive property provided that they have the same radicand. Such radicals are called like radicals.
Example Add or Subtract as indicated:
10 5 2 5 3 6 3 12
Example Add or Subtract as indicated:
7
x
98
x
2
x
5 28
x
Rationalizing Denominators
Rationalizing a denominator involves rewriting a radical expression as an equivalent expression in which the denominator no longer contains any radicals. If the denominator contains the square root of a natural number that is not a perfect square, multiply the numerator and the denominator by the smallest number that produces the square root of a perfect square in the denominator.
Let’s take a look two more examples:
3 2 8 3 2 4 3 2 4 4 2 4 4 2 3 2 8 3 2 4 3 2 4 4 2 4 4 2 24 2 32 24 2 32 2 24 2 32 24 2 32 2
Examples Rationalize the denominator:
7 6 7 18
Examples Rationalize the denominator:
2 3 2 5
Other Kinds of Roots
Examples Simplify:
3 8 3 8 4 16
The Product and Quotient Rules for nth Roots
Example Simplify:
5 4 5 40
Example Simplify:
3 64 27 3 250
Rational Exponents
Example Simplify:
3 81 4 32 5 3 48
x
3 5 3
x
2 1
Example Simplify:
2
x
5 4
x
3 1 4 81
x
2
Notice that the index reduces on this last problem.
Simplify:
(a) (b) (c) 9 2
x
9 2
x x
9
x
2 (d) 9 2
x x
81
x
3 4
x
Simplify:
(a) 7
x
4 3 3
x
2 1 2 21
x
4 5 (b) (c) (d) 63
x
4 5 21
x
4 7 63
x
4 7