document.write( "Question 861329: cos(x+pi/2)=-sin x
\n" ); document.write( " \n" ); document.write( "
Algebra.Com's Answer #518954 by math-vortex(648)\"\" \"About 
You can put this solution on YOUR website!
\r\n" );
document.write( "Hi there,\r\n" );
document.write( "\r\n" );
document.write( "PROBLEM:\r\n" );
document.write( "Prove that the identity is true.\r\n" );
document.write( "cos(x+pi/2)=-sin (x)\r\n" );
document.write( "\r\n" );
document.write( "Solution:\r\n" );
document.write( "Transform the left side of the identity until is is the same as the right side.\r\n" );
document.write( "cos(x + pi/2) = -sin (x)\r\n" );
document.write( "cos(pi/2 - (-x)) = -sin (x)\r\n" );
document.write( "\r\n" );
document.write( "Apply the co-function property: [cos(pi/2 + x) = sin (x)]\r\n" );
document.write( "sin (-x) = -sin (x)\r\n" );
document.write( "\r\n" );
document.write( "Apply the even/odd formula: [sin (-x) = - sin (x)]\r\n" );
document.write( "-sin (x) = - sin (x)\r\n" );
document.write( "\r\n" );
document.write( "That's it.\r\n" );
document.write( "\r\n" );
document.write( "Mrs. Figgy\r\n" );
document.write( "math.in.the.vortex@gmail.com\r\n" );
document.write( "
\n" ); document.write( "
\n" );