document.write( "Question 926811: If sinA+cosA=sqrt(2) then, A=45, how? \n" ); document.write( "
Algebra.Com's Answer #562475 by rothauserc(4718) You can put this solution on YOUR website! we are given \n" ); document.write( "sinA + cosA = sqrt(2) \n" ); document.write( "square both sides of = \n" ); document.write( "sin^2(A) + 2sinAcosA + cos^2(A) = 2 \n" ); document.write( "use identity sin^2(A)+cos^2(A) = 1 \n" ); document.write( "2sinAcosA +1 = 2 \n" ); document.write( "subtract 1 from both sides of = \n" ); document.write( "2sinAcosA = 1 \n" ); document.write( "divide both sides of = by 2 \n" ); document.write( "sinAcosA = 1/2 \n" ); document.write( "now substitute 45 degrees for A \n" ); document.write( "sin(45)*cos(45) = 1/2 \n" ); document.write( "0.707106781 * 0.707106781 = 1/2 \n" ); document.write( "0.5 = 0.5 \n" ); document.write( "answer checks, A = 45 degrees \n" ); document.write( " \n" ); document.write( " |