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3-2 Limits. Limit as x approaches a number. Just what is a limit?. A limit is what the ___________________________ __________________________________________ __________________________________________ __________________________________________
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3-2 Limits Limit as x approaches a number
Just what is a limit? A limit is what the ___________________________ __________________________________________ __________________________________________ __________________________________________ We may not actually get there. BUT a limit is not what you actually get to, but appear to get to. Asymptote: _________________________
What is the way to solve it? The easiest way to find the limit value is to plug the number in. Find the following
What about What is the restriction? (what can’t the denominator be) Factor the top and see if any terms cancel out If a term cancels out _______________________ ________________________________________ Graph the above equation
What if…. What do you think the answer is if you plug in the number and get ? What do you think the answer is if you plug in the number and get ?
The Harmonic Sequence The process used to find limits as x is based on the Harmonic Sequence The is 0. Think about it. What about As x gets really really huge, what will the reciprocal of the fxns approach?
Some rules of limits The great thing about limits is that the limit of something complicated can be done as the limit of all the pieces.
Taking the limit of Equations Steps to Solve: Divide each term by the highest overall power you see in the problem. Then evaluate each of the pieces. Then take the limit of each term.
Group Problems Find the following Now there is a shortcut “trick” to these problems. WITHOUT TALKING TO ANYONE tonight see if you can figure it out.
3-2 Limits Day 2
Anyone figure out the short cut? That’s right. You look for the overall high power. Overall High Power in top = _______________ Overall High Power in bottom = ____________ High Power in top and bottom are the same =_________________________________ __________________________________
Examples of Graphs So, you can see that the graphs have these vertical and horizontal lines that act as boundary lines. These are called Asymptotes. __________________________________________________________________________________________________________________
Asymptotes Vertical Asymptotes (VA): ___________________ ________________________________________ Hole: ___________________________________ Why does it still count if it goes away? ________________________________________ ________________________________________ Horizontal Asymptotes (HA): ________________ ________________________________________
Step 2 - Plot 3 points on each side of the vertical asymptote(s). • Graph
4 -1 **Graphs can cross a Horizontal Asym but not a vert Asym.
OK – to review for just a minute If a VA cancels out, ___________________ ___________________________________ If a VA doesn’t cancel out, ______________ ___________________________________ FYI: _______________________________ ___________________________________
So what is an oblique? Did you notice that all of the graphs that had vertical asymptotes also had limits? That is, the only functions that didn’t have limits had holes. What if you have no limit to the function, but as well have a vertical asymptote? Such as, Lets go graphing!
What happened? Well the vertical asymptote stayed, but the graph didn’t level. There was a diagonal line that acted as a boundary line. This diagonal line is the __________________ ___________________________________ So, lets figure out how to find the OA.
Finding OB Asymptote When the limit does not exist and there is a restriction, _________________________ ___________________________________ To find the OA, ___________________ into the numerator and ignore the remainder. That ______ is the oblique asymptote. Then graph the function the same way as if there was a VA.
Plot points and graph the function There will be a hole Check denominator of F(x) Cancels Doesn’t Exists Plot 3 points on each side of VA Take the Limit DNE Plot the OA as a dashed line; then plot 3 points on either side” of the OA Divide Denominator into Numerator
Group Problem 1 1
3.4 Day 1 Solving Fractional Equations
Find the x intercept of the graph X-int? ________________________
Solving the Inequalities • ______________________________ • _______________________________ • ______________________________ • ______________________________
3-4 Day 2 Word Problems
Work Rate Problems • ____________________________________ • _____________________________________ • _____________________________________ • _____________________________________ • ___________________________________ • ____________________________________
Jan can tile a floor in 14 hours. Together, Jan and her helper can tile the same floor together in 9 hours. How long would it take Bill to do the job alone? Work Rate x Time = Work done
Examples • The denominator of a fraction is 1 less than twice the numerator. If 7 is added to both numerator and denominator, the resulting fraction has a value of 7/10. Find the original fraction.
Example A student received grades of 72, 75 and 78 on three tests. What must he score on the next test to average a 80?
What is Synthetic Division? Synthetic Division ____________________ ___________________________________ • ________________________________ • ________________________________ • ________________________________ ___________________________________ ___________________________________
Lets try a problem Please divide by long division.
This is Synthetic Division This is the equivalent problem in synthetic division form: ___________________________________ ___________________________________
This is synthetic Division Try synthetic Division and see what you get: 1 4 3 1 4 3 -3
Here’s another problem with a bit of a twist. If your last name begins with A-M, do this problem by long division. If your last name begins with N-Z, do this problem by synthetic division.
What did you notice? Answer is doubled. When there is a number in front of the x, ________________________________________________________________________________________________________________________________________ **One other rule If one of the x’s are missing plug a zero in its place!
3.6 Day 2Why Synthetic Division? What use is this method, besides the obvious saving of time and paper?
The Remainder Theorem If is not a factor of F(x), then ___________________________________ ___________________________________ That is
The Factor Theorem If is a factor of F(x) then _________ When we talk about roots, it’s the same as zeros. Set equal to zero and solve.
How does this apply? • Find F(2) if • Is (x – 2) a factor of