document.write( "Question 167698: Let r(x)=x^2-3 and s(x)=x^3-6. Find r(s(-1)). \n" ); document.write( "
Algebra.Com's Answer #123607 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
First find \"s%28-1%29\" (the inner function)\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"s%28x%29=x%5E3-6\" Start with the second function.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"s%28-1%29=%28-1%29%5E3-6\" Plug in \"x=-1\".\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"s%28-1%29=-1-6\" Cube \"-1\" to get \"-1\".\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"s%28-1%29=-7\" Subtract.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "------------------------------------------\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Since \"s%28-1%29=-7\", this means that \"r%28s%28-1%29%29=r%28-7%29\" (just replace \"s%28-1%29\" with -7)\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So let's evaluate \"r%28-7%29\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"r%28x%29=x%5E2-3\" Start with the first function.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"r%28-7%29=%28-7%29%5E2-3\" Plug in \"x=-7\".\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"r%28-7%29=49-3\" Square \"-7\" to get \"49\".\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"r%28-7%29=46\" Subtract.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Since \"r%28-7%29=46\", this means that \"r%28s%28-1%29%29=46\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "========================================\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Answer:\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So the solution is \"r%28s%28-1%29%29=46\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Note: there is another way to do this which involves substituting \"s%28x%29\" into \"r%28x%29\" and evaluating the composite function at \"x=-1\". However, this method is a bit more complicated.
\n" ); document.write( "
\n" );