<p>Hey guys, I am in desperate need of help with the function problems on the math test. </p>
<p>I'm not referring to the really really basic ones, but with all mediums and hards I either get really lucky or don't even know how to start. </p>
<p>It sucks because I've been studying for the Jan 27 test for almost two months and it's come to the point where functions are the only problems I get wrong, so if any of you have any tips/strategies/methods/prayers, I'd really appreciate it!!</p>
<p>do you have any examples of the types of problems you mean?</p>
<p>I wish I had some specific examples, but really it's all problems that have f(x) and then they throw in other variables like g, and also when they have stuff like f(x(g))....I can't really even explain it haha.</p>
<p>Can't you provide an example of a problem involving functions that you got wrong? Since you're being vague, I can do little more than toss out a few links discussing functions.</p>
<p>Here are some elementary introductions:</p>
<p><a href="http://en.wikipedia.org/wiki/Function_(mathematics)%5B/url%5D">http://en.wikipedia.org/wiki/Function_(mathematics)</a>
<a href="http://en.wikibooks.org/wiki/Algebra/Functions%5B/url%5D">http://en.wikibooks.org/wiki/Algebra/Functions</a>
<a href="http://tutorial.math.lamar.edu/AllBrowsers/1314/FunctionDefn.asp%5B/url%5D">http://tutorial.math.lamar.edu/AllBrowsers/1314/FunctionDefn.asp</a></p>
<p>And here are some formal introductions:</p>
<p><a href="http://mathworld.wolfram.com/Function.html%5B/url%5D">http://mathworld.wolfram.com/Function.html</a>
<a href="http://planetmath.org/encyclopedia/Image2.html%5B/url%5D">http://planetmath.org/encyclopedia/Image2.html</a></p>
<p>As an example of function composition, suppose f(x) = x^2 + 1 and g(x) = 3x. What is f(g(5))? First evaluate g(5), then plug the result into f. g(5) = 3<em>5 = 15. Now plug 15 into f: f(15) = 15^2 + 1 = 226. That's it! We could also find f(g(x)) algebraically in terms of x instead of a concrete input. Since g(x) = 3x, we are evaluating f(3x) = (3x)^2 + 1 = 9x^2 + 1. We can check our work by plugging 5 into this expression: 9</em>5^2 + 1 = 9*25 + 1 = 225 + 1 = 226. It works!</p>
<p>Thanks a lot nilkn that example as well as the links helped a lot...thanks for answering I know I was very vague in my question!</p>
<p>I have the exact same problem. It's weird because I know how to SOLVE compound functions that look like f(g(x)) and arrive at the correct answer but I don't actually know what I'm doing. As far as graphing functions, forget it. I'm going to look over the links provided on this board and ask someone for help.</p>
<p>when you do, if you have an actual question it's a lot easier to help.</p>