<p>is there any online website where i can study the about functions as model in detail? which gives like the detailed explanation?</p>
<p>i went through sparknotes and barron2400 but there this topic was concise and i couldnt understand much out of 'em (in barrons, the questions i solved were very easy and comparatively easy as when i solved the actual SAT questions from the topic, from the BB)
and its just the questions from this topic that makes me stumble from a 700+ mark in math.</p>
<p>any website to help me explain the graphs with curve lines - thing?
or someone please just tell me <em>ALL</em> the (important) formulas used from the topic (in the SAT-1 math)?</p>
<p>...and no, i cant get much help from school either!
thanks all.</p>
<p>somebody? please?
come on guys</p>
<p>I think that your question is not clear enough for anyone to answer. Are you talking about the subject of mathematical modeling? There is none of this on the SAT. Are you just concerned with word problems that involve functions? On the SAT these problems generally just involve plugging some numbers into a function - there is no need to learn a whole subject about this. I’m not even clear if you are asking about the regular SAT or the Subject test.</p>
<p>Why don’t you post a problem of the type you are worried about, and maybe we can help.</p>
<p>Dr.Steve, i an enquiring about SAT 1 math.
Topic- Functions
Subtopic- Function as Models.
The questions in which we are given a formula and asked about the graph.
As like : the graph shown abovr represents f(x) and f(x+a)+b where a and b are constants. Which of the following is the ordered pair (a,b). And then theres a graph shown above, etc?
A(x-h)-k?!</p>
<p>Also about questions like
F(x)= x^2 + x - 42 and f(p-1)=0
Positive value of x?
And,
F(x)= x^2 -5x +2 and g(x)= f(x-4)
Find positive root of equation-
f(x)= g(2)</p>
<p>I’m not sure why you are listing this as “Functions as Models.” The types of questions you mention here have nothing to do with models or modelling. The first type of question you’re asking about is “Transformations of functions” and more specifically “horizontal and vertical shifts.” The second type of question is about “Quadratic Functions.”</p>
<p>Now first of all, note the 2 types of questions you are referring to have only appeared as Level 5 questions on actual SATs. This means you should only be worrying about these types of questions if your current SAT math ability is at least a 700 (or at least close to it). I will address each of these two types of questions in separate replies below.</p>
<p>Everything you need to know about shifting:</p>
<p>Let y=f(x) be a function and c a positive number. Here is how you shift the graph:</p>
<p>f(x)+c shift up c units
f(x)-c shift down c units
f(x+c) shift left c units
f(x-c) shift right c units</p>
<p>For example the graph of f(x)=(x+5)^2 - 2 is the same as the graph of f(x)=x^2 shifted left 5 units and down 2 units.</p>
<p>Note: the left and right behavior of shifting might seem opposite of what you think it should be. The up and down behavior seems correct.</p>
<p>Note 2: In practice, if you forget these rules for shifting it’s not a big deal, you can simply plug in a point and see if it winds up in the right spot.</p>
<p>Let f(x)= x^2 + x - 42. Find the positive value of p for which f(p-1)=0</p>
<p>First let’s find where f(x)=0. There are many ways to do this.</p>
<p>(1) factoring
(2) quadratic formula
(3) graphing calculator
(4) taking guesses
(5) completing the square
(6) trying the factors of 42</p>
<p>For the SAT I would usually recommend (4), unless you are very good at factoring. I will factor:</p>
<p>x^2 + x - 42 = (x+7)(x-6). Thus f(x)=0 when x=-7 or x=6. We will use 6 since it is more likely to be the one we want since we are looking for a positive value of p (if 6 were to not work we would simply use -7 next).</p>
<p>Now we just showed that f(6)=0. So p-1=6, and p=7.</p>
<p>Note: I don’t think the last question you posted makes sense.</p>