Solving quadratic equations by finding square roots
Square root of a number
All positive real numbers have two square roots: a positive square root (called principal square root) and a negative square root.
x2 = 16, what can x be
whenever we have a variable squared and we take the square root we must account for both positive and
negative
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if d > 0 then x2 = d has two solutions, x = Solve Ex 1) 3x2 ­ 48 = 0
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Title: Feb 10­7:26 AM (1 of 4)
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if b2 = a then b is the square root of a
Square roots
if 32 = 9 then 9 = 3
Rational numbers include perfect square roots
non perfect square roots are irrational
Can you name some perfect square roots?
Title: Mar 14­7:31 AM (2 of 4)
Simplest Radical Form
this is what you do
when it is NOT a
perfect square root
Properties of radicals
ab
To be in simplest radical form, NO number beneath the radical can have a
PERFECT SQUARE as one of its factors!!!!!!!!!!!!!!!!!!!!!!!!!
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NO radicals appear in the denominator!!!!
Put all answers in simplest radical form
Ex 1) 8
ex 3)
72
Ex 5) 32
Ex 2)
18
Ex 4)
3
Assignment page 514, numbers 4 ­ 7, and 10 ­ 33.
Title: Apr 21­7:16 AM (3 of 4)
18) from test
Title: May 2­9:29 AM (4 of 4)