<p>Its from a practice test for math iic</p>
<p>If the point (-5,-2) is on the graph of y=f(x), then which of the following points must also be on the graph og y=f(-|x|)?</p>
<p>Answer says (5,-2) and the explanation is here:
<a href="http://www.rusenmeylani.bizland.com/cropped%20images%202C/2-04-11.jpg%5B/url%5D">http://www.rusenmeylani.bizland.com/cropped%20images%202C/2-04-11.jpg</a></p>
<p>Can somebody explain?</p>
<p>Also, another question from Meylani's Math iic tests</p>
<p>If f(x) is defined by f(x)=sin(cos(x), then f(250degrees) = ?</p>
<p>The answer explanation is <a href="http://www.rusenmeylani.bizland.com/cropped%20images%202C/2-04-32.jpg%5B/url%5D">http://www.rusenmeylani.bizland.com/cropped%20images%202C/2-04-32.jpg</a></p>
<p>why must one convert to radians in the last step?</p>
<p>Meylani, if you are reading this, please explain!
BTW, these were not on the correction lists that he posted on the the website</p>
<p>u can do it w/ a TI-83 calculator
by just switching to degree mode</p>
<p>and entering sin(cos(250)) or if u want to stay in radian mode you can always do sin(cos(250*(pi)/180))</p>
<p>I don't get the original question... I don't see how that is the right answer (5,-2). Meylani please answer!</p>
<p>Variance, the problem is that I dont understand why the answer explanation first did cos (250) in degrees mode, get the value, and then do sin(previous value) in degrees mode</p>
<p>Ok, see, plug in the answer to the original question.</p>
<p>y = f(-|5|)... which simplifies to y = f(-5).</p>
<p>Since we know (-5,-2) was an answer, we know that (5,-2) is an answer (since f(-|5|) = f(-5) = -2.</p>
<p>Bump ||||
^
^</p>
<p>First of all y=f(-|x|) is an even function. So if (-5,-2) is on the graph so must (5, -2) be.</p>
<p>On the other hand sin(cos(250 degrees)) is a tricky question.
First calculate cos(250 degrees) in degree mode, then calculate sin(result) in radian mode.</p>
<p>I understand the first one</p>
<p>but for the second one, why does one have to convert to radian mode inthe second step? there was no indication whatsoever for switching.</p>
<p>As a rule of thumb; if you see that there is no degree sign, you should do your calculation in the radian mode.</p>
