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If the distance between the points (-1,4) and(4,9) is 13 units then sind the value of y. |
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Answer» Answer: Let A and B be the two POINTS such that A(3,x) and (−2,−6) respectively. As we know that distance between the two points (x 1 ,y 1 ) and (x 2 ,y 2 ) is- d= (x 2 −x 1 ) 2 +(y 2 −y 1 ) 2
Therefore, AB= (−2−3) 2 +(−6−x) 2
⇒AB= 25+(36+x 2 +12x)
But given that AB=13 units ∴ 25+(36+x 2 +12x) =13 Squaring both sides, we have ( 25+(36+x 2 +12x) ) 2 =(13) 2
25+36+x 2 +12x=139 x 2 +12x+61−139=0 x 2 +12x−78=0 Now by quadratic formula, we have x= 2×1 −12± (12) 2 −4(−78)(1)
⇒x= 2 −12± 144+312
⇒x= 2 −12± 456
⇒x=−6± 114
Hence the value of x is (−6+ 114 ) or (−6− 114 ). Step-by-step EXPLANATION: |
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