<p>Hi guys!</p>
<p>I have some troubles with #3 from page 367. What does f(x)=f(-x) represent? I've never seen that kind of function notation in my country. It's not the the same as y=(-x), is it? </p>
<p>Why is the answer C) and not B) ?</p>
<p>Thank you very much!</p>
<p>Do you understand what f(x) means? It means that if you plug in a value x, you will get f(x) as a result. Alternatively I could call it y.</p>
<p>So f(x)=f(-x) means that when I plug in a value, say 3, I should get the same thing as if I plug in -3. So what does this mean graphically? Well, it means the left and right sides are the same; in other words it is symmetric over the y-axis. So the answer is C.</p>
<p>Hope this helps :)</p>
<p>Yes thanks a lot, I really appreciate it!</p>
<p>Sorry for the dumb question baha. I'm used to work with f(x) as one part of the equation, not two, so that is why I got confused.</p>
<p>Since the question do not tell us how to transform x's to y's (like f(x)=3x+89), any graph would do, as long as it is symmetric over the y-axis, right?</p>
<p>Right. This question is testing your ability to read a graph and know how it relates to the function, not your ability to algebraically evaluate functions.</p>