document.write( "Question 252486: 2sin^2x+3cosx=3 \n" ); document.write( "
Algebra.Com's Answer #184428 by drk(1908)![]() ![]() ![]() You can put this solution on YOUR website! Here is the original problem: \n" ); document.write( "(i) 2sin^2x+3cosx=3 \n" ); document.write( "We have an identity for sin^2(x). \n" ); document.write( "Sin^2(x) + Cos^2(x) = 1. \n" ); document.write( "Solving for Sin^2(x), we get \n" ); document.write( "sin^2(x) = 1 - cos^2(x) \n" ); document.write( "Now, by substitution into (i), we get \n" ); document.write( "2(1 - cos^2(x)) + 3cos(x) - 3 = 0 \n" ); document.write( "2cos^2(x) - 3cos(x) + 1 = 0. \n" ); document.write( "Factoring, we get \n" ); document.write( "(2cos(x) - 1)(cos(x) - 1) = 0. \n" ); document.write( "Solve each parenthesis for x. \n" ); document.write( "(2cos(x) - 1) = 0 \n" ); document.write( "cos(x) = 1/2. \n" ); document.write( "x = 60 degrees or 300 degrees ; radians = pi/3, 5pi/3 \n" ); document.write( "(cos(x) - 1) = 0 \n" ); document.write( "cos(x) = 1 \n" ); document.write( "x = 0 degrees ; 0 radians. \n" ); document.write( "----- \n" ); document.write( "So, your answers are: 0, 60 degrees, 300 degrees. \n" ); document.write( " |