document.write( "Question 622504: please help me solve:\r
\n" ); document.write( "\n" ); document.write( "4tan^2u-1= tan^2u
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Algebra.Com's Answer #391439 by KMST(5328)\"\" \"About 
You can put this solution on YOUR website!
\"4%28tan%28u%29%29%5E2-1=%28tan%28u%29%29%5E2\"
\n" ); document.write( "Let me change the name of \"tan%28u%29\" for a little while, to save ink and confusion.
\n" ); document.write( "\"tan%28u%29=x%5E2\"
\n" ); document.write( "Now I can write the confusing equation as
\n" ); document.write( "\"4x%5E2-1=x%5E2\" --> \"3x%5E2-1=0\" --> \"3x%5E2=1\" --> \"x%5E2=1%2F3\"
\n" ); document.write( "Back into trigonometry,
\n" ); document.write( "\"%28tan%28u%29%29%5E2=1%2F3\"
\n" ); document.write( "You should know an angle that is a solution.
\n" ); document.write( "(You should sine and cosine of 0, 30,45,60, and 90 degrees, or at least have a chart with their exact values handy).
\n" ); document.write( "\"30%5Eo\" or \"pi%2F6\" is a solution.
\n" ); document.write( "\"sin%2830%5Eo%29=1%2F2\", \"cos%2830%5Eo%29=sqrt%283%29%2F2\", and \"tan%2830%5Eo%29=sin%2830%5Eo%29%2Fcos%2830%5Eo%29=1%2Fsqrt%283%29\"
\n" ); document.write( "(although teachers prefer the equivalent expression \"tan%2830%5Eo%29=sqrt%283%29%2F3\" because they do not like square roots in denominators).
\n" ); document.write( "You also should know that the supplementary angle, \"150%5Eo\" or \"5pi%2F6\" has the opposite tangent:
\n" ); document.write( "\"tan%28150%5Eo%29=-1%2Fsqrt%283%29\"
\n" ); document.write( "So those two angles are solutions.
\n" ); document.write( "There are many more solutions, because the tangent function has a period of \"180%5Eo\" or \"pi\", so to include all solutions we need to add \"n%2Api\" with \"n\" defined as an integer to the solutions above.
\n" ); document.write( "(I am not going to continue with the degrees, because I'm sure your teacher likes pies better than degrees).
\n" ); document.write( "In radians, and putting all solutions in one formula, my solution set is
\n" ); document.write( "\"u=n%2Api+%2B-+pi%2F6\" for all n integers
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