document.write( "Question 1051725: find the range of values of k for which kx+y=3 meets x²+y²=5 in two distinct points \n" ); document.write( "
Algebra.Com's Answer #667209 by Fombitz(32388)\"\" \"About 
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All the lines go through the point (0,3).
\n" ); document.write( "The line tangent to the circle and going through the point (0,3) would make a right triangle together with the radius of the circle with the hypotenuse being from the origin to the point (0,3).
\n" ); document.write( "\"3%5E2=5-D%5E2\"
\n" ); document.write( "\"D=2\"
\n" ); document.write( "So then build a circle centered at (0,3) with a radius of 2.
\n" ); document.write( "Then look for the two intersection points of that circle with the original circle.
\n" ); document.write( "Those two points are the two tangents points that the lines would make with the original circle and will provide the limits for \"k\".
\n" ); document.write( "The equation of the new circle would be,
\n" ); document.write( "\"x%5E2%2B%28y-3%29%5E2=2%5E2\"
\n" ); document.write( "\"x%5E2%2B%28y-3%29%5E2=4\"
\n" ); document.write( "So using the original equation,
\n" ); document.write( "\"x%5E2%2By%5E2=5\"
\n" ); document.write( "\"x%5E2=5-y%5E2\"
\n" ); document.write( "Substitute this into the new equation,
\n" ); document.write( "\"5-y%5E2%2B%28y-3%29%5E2=4\"
\n" ); document.write( "\"5-y%5E2%2By%5E2-6y%2B9=4\"
\n" ); document.write( "\"-6y%2B14=4\"
\n" ); document.write( "\"-6y=-10\"
\n" ); document.write( "\"y=5%2F3\"
\n" ); document.write( "So them.
\n" ); document.write( "\"x%5E2%2B%285%2F3%29%5E2=5\"
\n" ); document.write( "\"x%5E2%2B25%2F9=5\"
\n" ); document.write( "\"x%5E2=45%2F9-25%2F9\"
\n" ); document.write( "\"x%5E2=20%2F9\"
\n" ); document.write( "\"x=0+%2B-+%282%2F3%29sqrt%285%29\"
\n" ); document.write( "So now you have two points on each line, you can solve for \"k\".
\n" ); document.write( "\"kx%2By=3\"
\n" ); document.write( "\"k%282%2F3%29sqrt%285%29%2B5%2F3=3\"
\n" ); document.write( "\"k%282%2F3%29sqrt%285%29=9%2F3-5%2F3\"
\n" ); document.write( "\"k%282%2F3%29sqrt%285%29=4%2F3\"
\n" ); document.write( "\"k=2%2Fsqrt%285%29\"
\n" ); document.write( "\"k=%282%2F5%29sqrt%285%29\"
\n" ); document.write( "with the other solution for k being the reciprocal,
\n" ); document.write( "\"k=-%282%2F5%29sqrt%285%29\"
\n" ); document.write( "So the tangent points are the limit for one distinct point of contact so for two distinct points don't include these points so,
\n" ); document.write( "\"-%282%2F5%29sqrt%285%29%3Ck%3C%282%2F5%29sqrt%285%29\"
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