<p>So I just bought the TI-nspire CAS calculator because I had no graphing calculator at all ( no one uses them over here). This calculator has tons of functions that i'll probably never know all of them.
But which ones should I do my best to understand for the SAT 1 (and Math 2 in the future) to get the best out of it.
In addition, I saw I can write notes in it, do people just write formulas and stuff in there? doesn't seem very legit lol.</p>
<p>Thanks in advance for the help.
Tomer.</p>
<p>If you can find the four functions, parentheses, pi, the ^ and ^2 buttons, and maybe *10^x, you shouldn’t need anything else. You might need factorials, but even that is kind of rare. There’s really nothing on the SAT that requires any kind of advanced assistance. There’s not even trig. For me, the biggest benefits to having an nspire lie in the interface, keyboard, and screen resolution, not really any added functions. Your calculations are expressed in an easy to read way on the scratchpad, so it’s easy to tell if you’ve entered something correctly</p>
<p>I hardly touched my nspire, and I got a 770M on my first and only test so far. That was the January 2013 test, and 770M = 1 missed, none omitted. Just know what you’re doing mathematically, and use your calculator to get it done faster, because it really can’t take the test for you.</p>
<p>In general I don’t have that much of a problem with math i’m currently scoring around 700’s and I got till MAY, still haven’t gone over all the material, but just wondering if it may have some emergency help in functions or double equations or perhaps display Y in terms of X, questions that I hate lol :P</p>
<p>I found that the math review section of the College Board’s Official Guide to the SAT (the blue book) in chapters 15 - 18 was a great tool to use in preparing for the math section, as it will remind you of many basic mathematical principles and properties that will really help in answering questions. Even if you already know them, it is good to see them again and have them fresh in your mind before you test. </p>
<p>As for the specific problem types you mentioned, can you find examples of these so I could see just what you’re talking about? Perhaps I could tell you easy ways to solve them.</p>
<p>1.If X^2 + kx +15 = (x + t)*(X + 5) for all values of x and if k and t are constants, what is the value of k?</p>
<ol>
<li>IF A > 1 in the equations a^x/a^y = a^-6 and a^x * a^y = a^12 what is the value of y?</li>
</ol>
<p>1st is multiple choice, 2nd is free response.
Thanks :)</p>
<ol>
<li><p>x^2 + kx + 15 = (x + t) * (x + 5) = x^2 + 5x + tx + 5t
At this point, you can subtract x^2 from both sides, and you have:
kx + 15 = 5x + tx + 5t = (5 + t) * x + 5t
The constant “t” must equal 3, and k would therefore be 5 + 3 = 8.</p></li>
<li><p>The given information a > 1 just removes the problem of multiplication identity. Recall that b^n/b^x = b^(n - x) and b^n * b^x = b^(n + x). So, from the given information, you know that x - y = -6, and x + y = 12. The two numbers with a difference of -6 and a sum of 12 are 3 and 9, therefore x = 3 and y = 9. The answer is 9.</p></li>
</ol>
<p>Hope those explanations helped.</p>
<p>kx + 15 = (5 + t) * x + 5t</p>
<p>How did you get from that to the values of t and k, just assume that t is 3 becasue 5*3=15 and then make k equal to the (5+t)? how is it shown mathematically in a full way?</p>
<p>and for question 2, thanks, I got it now lol :)</p>
<p>If “k” did not equal (5 + t), then the two functions y = kx + 15 and y = (5 + t)x + 5t would not be equal for all values of x; you must account for variance in the x value, as t is a constant, so 5t will be the same value no matter what x is. The only way to do this is ensure that x will be multiplied by the same value in both equations, and so k must equal 5 + t. From there, you know that 5 * t = 15, therefore t = 3, and k = 5 + 3 = 8.</p>
<p>If you’re still confused, I’m not sure how better to phrase it. Really, I don’t think this would be a real SAT math question; they’re usually not as involved as this. Where did you find this example?</p>
<p>I found it in a previous test, I think its from 2005 its question number 13 in section 9.</p>
<p>I think I do get it now, hopefully i’ll run into something similiar to that when i’m practicing, then i’ll understand it ok.
Thanks :)</p>