document.write( "Question 1200824: Using the chain rule, show that the following statements are always true:\r
\n" ); document.write( "\n" ); document.write( "a) If f(x) is an odd function then f'(x) is an even function \r
\n" ); document.write( "\n" ); document.write( "b) If f(x) is an even function then f'(x) is an odd function
\n" ); document.write( "

Algebra.Com's Answer #835121 by Edwin McCravy(20055)\"\" \"About 
You can put this solution on YOUR website!
\r\n" );
document.write( "g(x) is an even function if and only if g(-x) = g(x)\r\n" );
document.write( "g(x) is an odd function if and only if g(-x) = -g(x)\r\n" );
document.write( "
a) If f(x) is an odd function then f'(x) is an even function
\r\n" );
document.write( "\r\n" );
document.write( "\"f%28-x%29=-f%28x%29\"\r\n" );
document.write( "\r\n" );
document.write( "Take derivatives of both sides:\r\n" );
document.write( "\r\n" );
document.write( "\"%22f%27%28-x%29%2A%28-1%29%22\"\"%22%22=%22%22\"\"%22-f%27%28x%29%22\"\r\n" );
document.write( "\r\n" );
document.write( "\"%22-f%27%28-x%29%22\"\"%22%22=%22%22\"\"%22-f%27%28x%29%22\"\r\n" );
document.write( "\r\n" );
document.write( "Divide both sides by -1\r\n" );
document.write( "\r\n" );
document.write( "\"%22f%27%28-x%29%22\"\"%22%22=%22%22\"\"%22f%27%28x%29%22\"\r\n" );
document.write( "\r\n" );
document.write( "So f'(x) is an even function.\r\n" );
document.write( "\r\n" );
document.write( "-----------------------------------------------------------------\r\n" );
document.write( "\r\n" );
document.write( "
b) If f(x) is an even function then f'(x) is an odd function
\r\n" );
document.write( "\r\n" );
document.write( "\"f%28-x%29=-f%28-x%29\"\r\n" );
document.write( "\r\n" );
document.write( "Take derivatives of both sides:\r\n" );
document.write( "\r\n" );
document.write( "\"%22f%27%28-x%29%2A%28-1%29%22\"\"%22%22=%22%22\"\"%22-f%27%28-x%29%2A%28-1%29%22\"\r\n" );
document.write( "\r\n" );
document.write( "\"%22-f%27%28-x%29%22\"\"%22%22=%22%22\"\"%22f%27%28-x%29%22\"\r\n" );
document.write( "\r\n" );
document.write( "Divide both sides by -1\r\n" );
document.write( "\r\n" );
document.write( "\"%22f%27%28-x%29%22\"\"%22%22=%22%22\"\"%22-f%27%28-x%29%22\"\r\n" );
document.write( "\r\n" );
document.write( "So f'(x) is an odd function.\r\n" );
document.write( "\r\n" );
document.write( "Edwin
\n" ); document.write( "
\n" );