document.write( "Question 520169: Find sinalpha if tan(alpha/2)=1/root2 \n" ); document.write( "
Algebra.Com's Answer #345975 by stanbon(75887)![]() ![]() ![]() You can put this solution on YOUR website! Find sin(alpha) if tan(alpha/2) = 1/sqrt(2) \n" ); document.write( "------ \n" ); document.write( "Since tan(alpha/2) = y/x = 1/sqrt(2), \n" ); document.write( "y = 1 when x = sqrt(2) \n" ); document.write( "So, r = sqrt[1^2+(sqrt(2))^2] = sqrt(1+2) = sqrt(3) \n" ); document.write( "---- \n" ); document.write( "Then sin(alpha/2) = y/r = 1/sqrt(3) \n" ); document.write( "and cos(alpha/2) = x/r = sqrt(2)/sqrt(3) = (1/3)sqrt(6) \n" ); document.write( "------------- \n" ); document.write( "Finally, sin(alpha) = sin(2(alpha/2)) = 2sin(alpha/2)*cos(alpha/2) \n" ); document.write( "= 2 \n" ); document.write( "--- \n" ); document.write( "= (2sqrt(6)/(3*sqrt(3)) \n" ); document.write( "------ \n" ); document.write( "= (2/3)[sqrt(18)/3] \n" ); document.write( "--- \n" ); document.write( "= (2/3)sqrt(2) \n" ); document.write( "==================== \n" ); document.write( "Cheers, \n" ); document.write( "Stan H. \n" ); document.write( "====================\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |