document.write( "Question 765156: Every time I try to solve this equation I come up with no solution, but that answer is incorrect. Help please?
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document.write( "[(11-x^2)^1/2]-[2/(11-x^2)^1/2]=1 \n" );
document.write( "
Algebra.Com's Answer #465975 by rothauserc(4718)![]() ![]() You can put this solution on YOUR website! [(11-x^2)^1/2]-[2/(11-x^2)^1/2]=1 \n" ); document.write( "let u = [(11-x^2)^1/2] and then we have \n" ); document.write( "u^2 -2 = u and \n" ); document.write( "u^2 -u -2 = 0, factor this \n" ); document.write( "(u-2) * (u+1) = 0, so we have \n" ); document.write( "===================================================================== \n" ); document.write( "[(11-x^2)^1/2] = 2 \n" ); document.write( "square both sides \n" ); document.write( "11 -x^2 = 4 \n" ); document.write( "multiply both sides of = by -1 \n" ); document.write( "x^2 -11 = -4 \n" ); document.write( "x^2 = 7 \n" ); document.write( "x = sqrt(7) \n" ); document.write( "================================================================== \n" ); document.write( "[(11-x^2)^1/2] = -1 \n" ); document.write( "square both sides \n" ); document.write( "11 -x^2 = 1 \n" ); document.write( "multiply both sides of = by -1 \n" ); document.write( "x^2 -11 = -1 \n" ); document.write( "x^2 = 10 \n" ); document.write( "x = sqrt(10) \n" ); document.write( "===================================================================== \n" ); document.write( "now we substitute back in original equation to check \n" ); document.write( "(11 -7)^1/2 - 2 / (11-7)^1/2 = 1 \n" ); document.write( "2 - (2 / 2) = 1 \n" ); document.write( "2 - 1 = 1 \n" ); document.write( "x = sqrt(7) checks out \n" ); document.write( "======================================================= \n" ); document.write( "now for x = sqrt(10) \n" ); document.write( "(11-10)^1/2 - 2 / (11-10)^1/2 = 1 \n" ); document.write( "1 -2/1 = -1 \n" ); document.write( "this does not check out \n" ); document.write( "========================================================= \n" ); document.write( "our answer is x = sqrt(7) = 7^1/2 \n" ); document.write( "========================================================== \n" ); document.write( " |