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Square Root
If x2=a, then x=± (a≥0) |
Example 1.x2=3 → x=± 2.x2=4 → x=±=±2 3.x2=12 → x=±=±2 |
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Corollary 1
If ax2=b, then x=± (a>0, b≥0)
(Because)
ax2=b → x2= → x=± |
Example 1.3x2=2 → x2= → x=±=±=± 2.9x2=5 → x2= → x=±=± 3.5x2=12 → x2= → x=±=± =±=± |
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Corollary 2
If (x+a)2=b, then x=−a± (b≥0)
(Because)
(x+a)2=b → x+a=± → x=−a± |
Example 1.(x+1)2=3 → x+1=± → x=−1± 2.(x−2)2=9 → x−2=±=±3 → x=2±3=5, −1 3.2(x−3)2=5 → (x−3)2= → x−3=±=± → x−3=± → x=3±= |
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QuestionSolve the following equations by the Square Root Method. (Choose a correct answer from the right column.) |
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