3.8 ­ Finding and Estimating Square Roots.notebook
September 16, 2011
When you square an integer, that number is called a Perfect Square
Chapter 3 Section 8
Why???
Finding and Estimating Square Roots
Square Root is the number being multiplied by itself to get the area (the side of the square)
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How do we "undo" a squared number? ?
42 = 16
2 (­4) = 16
Every positive number has 2 square roots
- Principal Square Root (positive)
- Negative Square Root
Notice how this 2 means there will be 2 answers!
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Perfect Squares: squares with no decimals
they work out perfectly
Square Root Rule We don't take a square root of negative numbers.
WHY????
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Perfect Squares
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3.8 ­ Finding and Estimating Square Roots.notebook
September 16, 2011
What if we are asked to find the What is the square root of 18?
Estimate:
Estimate the answer by using your knowledge of perfect squares!
Exact: Round to the nearest hundredth (2 places)
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What is the square root of ­92?
What is the square root of 32?
Estimate:
Estimate:
Exact: Round to the nearest hundredth (2 places)
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Hmm....will this work???
Exact: Round to the nearest hundredth (2 places)
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Hmm....will this work???
?
?
Multiplication Property of Square Roots
(a and b must be whole numbers!!)
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3.8 ­ Finding and Estimating Square Roots.notebook
Woah! What about September 16, 2011
?
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