document.write( "Question 1118318: Find all the points having an x-coordinate of 9 whose distance from the point (3, -2) is 10.
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document.write( "(9, 13), (9, -7)
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document.write( "(9, 2), (9, -4)
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document.write( "(9, 6), (9, -10)
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document.write( "(9, -12), (9, 8)
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Algebra.Com's Answer #733623 by greenestamps(13203) You can put this solution on YOUR website! \n" ); document.write( "The formal algebraic solution method which has you finding the answer by solving a quadratic equation is of course valid. But the problem can be made much easier than that. \n" ); document.write( "You are looking for the two points on the line x=9 whose distance from (3,-2) is 10. \n" ); document.write( "The horizontal distance from (3,-2) to the line x=9 is 9-3 = 6. So that horizontal line segment, the line x=9, and the segments from (3,-2) to the points we are looking for will form two right triangles, each with one leg 6 and hypotenuse 10. \n" ); document.write( "Quick use of the Pythagorean Theorem (or the recognition that 6-8-10 is a multiple of the common 3-4-5 right triangle) make the other leg of each right triangle 8. \n" ); document.write( "Then the two points on the line x=9 that are 8 units from y=-2 are -2+8 = 6 and -2 -8 = -10. \n" ); document.write( "So the two points we are looking for are (9,-10) and (9,6). \n" ); document.write( " |