document.write( "Question 864960: I previously asked this question and got this solution (after question). But I would appreciate further clarification.
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document.write( "The line with the equation y=mx is tangent to the circle with centre (-8,0) and radius 4 at the point P(x,y).
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document.write( "a)find x coordinate of P in terms of m
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document.write( "b)Show that m = +- sqrt (3)/ 3 and hence find the coordinates of P
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document.write( "(x+8)^2+y^2=16
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document.write( "(x+8)^2+y^2=16, y=mx
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document.write( "m = 1/sqrt(3), x = -6, y = m x
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document.write( "m =-1/sqrt(3), x = -6, y = m x
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document.write( "+-1/sqrt(3)=+-sqrt(3)x/3
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document.write( "y=+-sqrt(3)x/3
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document.write( "x=-6, y =2sqrt(3)
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document.write( "P=(-6,2sqrt(3))
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document.write( "Can you please provide further clarification-
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document.write( "Step 3 and 4-
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document.write( "m = 1/sqrt(3), x = -6, y = m x
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document.write( "m =-1/sqrt(3), x = -6, y = m x
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document.write( "How was the x coordinate found.
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document.write( "Step 5
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document.write( "+-1/sqrt(3)=+-sqrt(3)x/3
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document.write( "what is happening here for one to become the other.\r
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document.write( "I need this explained very simply So i i can understand it. Especially my queries about the steps. Thank you very much.\r
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document.write( "
Algebra.Com's Answer #521431 by KMST(5328)![]() ![]() You can put this solution on YOUR website! I see several ways to get the answer. I cannot tell if one of the ways I would use was used in the first answer you got. Maybe the reasoning was through a different way. I can explain one or more ways. However, I am a long-winded explainer, so you may get more explanation that you bargained for. \n" ); document.write( " \n" ); document.write( "USING GEOMETRY AND ANALYTIC GEOMETRY: \n" ); document.write( "The tangent to a circle is perpendicular to the radius at the point of tangency, so I would draw the sketch like this: \n" ); document.write( " \n" ); document.write( "The two triangles are congruent, with P(x,y) and Q(x,-y), so I only need to solve OPC. \n" ); document.write( "I know that the length of leg CP is \n" ); document.write( " \n" ); document.write( "That tells me that the angle \n" ); document.write( "and OPC is a 30-60-90 triangle. \n" ); document.write( "From the tangent of that \n" ); document.write( " \n" ); document.write( "We multiply times \n" ); document.write( "so m = +- \n" ); document.write( "Of course, OP is the line with the negative slope, and OQ is the line with the positive slope. \n" ); document.write( "For OP, \n" ); document.write( "for OQ, \n" ); document.write( "The altitude of that right triangle splits it into two similar right triangles, CPM, and OPM. \n" ); document.write( "As the ratio of short leg to hypotenuse for OPC is \n" ); document.write( " \n" ); document.write( "For OP, \n" ); document.write( "and for P, \n" ); document.write( "On the other hand, for Q, \n" ); document.write( " \n" ); document.write( "WITHOUT MENTIONING GEOMETRY (too much): \n" ); document.write( "OK, we need to know the equation of the circle, and I could call that analytical geometry, but you learn that in algebra 2 too. \n" ); document.write( "The equation of a circle with radius \n" ); document.write( " \n" ); document.write( "For the circle in your problem, that would be \n" ); document.write( " \n" ); document.write( "If \n" ); document.write( "so \n" ); document.write( " \n" ); document.write( "For what value of \n" ); document.write( "A quadratic \n" ); document.write( "and then \n" ); document.write( "In the case of \n" ); document.write( " \n" ); document.write( "It will have one and only one real solution when \n" ); document.write( " \n" ); document.write( "So \n" ); document.write( "m = +- \n" ); document.write( "In either case, we can use \n" ); document.write( " \n" ); document.write( "That is the \"x coordinate of P in terms of m\" as your problem asked for. \n" ); document.write( "Maybe this is the way your teacher/book expected you to solve the problem. \n" ); document.write( "We can calculate further (apparently not required by your problem): \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " |