November 17, 2006

Solving Inequalitie Equtions & A Splash of Review

Well well well. Another friday scibe post!
Okay. So lets get this scribe going.

Minutes after the 5th period bell, we all walk into our Pre-Cal class, as we do everyday and by our dismay we spot Mr. K holding a small stalk of papers. Since we're all "smarter then the average bear", we immediately knew a lovely quiz was coming in our direction. So after a brief discussion of wither or not we should include quizes for marks, we all got to work. The quiz was nothing new; a nicely summed up quiz about everything we learned so far in 'Analytic Geomtry'.

After self marking our peer's quizes, Mr. K placed the following questions on the board.


Question 1:


Okay, so we haven't seen much of these before and you may be a little puzzled.
BUT- think back to the Mathmatician who set the house on fire
"Turn the problem into something we already know how to solve"

First and foremost- Ignore the "<" for now, think of it as an "="

And if we move the 6 to the opposite side..

Why what do we have here? A parabola! Not too terrifying is it?

Okay so lets place the "<" back.


Before actually solving this equation, it would help to understand what infact the question is asking. Well what we're trying to do is-
"Find the values of X where this parabola will have negative values"

So first we must factor the equation we came up with

Once we get the two roots, you must draw the line graph (it will be included for marks for the final answer). Finally pick any point in each of the 3 regions and sub it into the equation.

Answer: (-3, 2)
Remember! we use round brackets "( )" because we know the -3 and 2 are not included because the original equation did not include "≤" (less then AND equals to)

Question 2:

Remember! The values in the absolute signs "x" can be both negative and positive, leaving us with two cases.

Case #1
x=-1 check: it works!

Case #2
x=4 check: it works!

Okay that was simple enough, BUT- what if we had..

Yikes! Do not fear, remember- ignore the "<" and treat it as an "=" for now.

So we'd continue to solve just like before-
Case #1

Case #2

Answer: (-∞,1)U(4,∞)
"U" - Union, that group together with this group

To be finished soon, very soon.
Sorry folks!

Homework assignment: All the questions you didn't get done on the past exercises (up to Exercise 28).
Mondays scribe will be Mel!isa

Enjoy your weekend!

1 comment:

  1. edcee, I was just wondering , who's the scribe?and I forgot the homework coz I remember Mr. K saying about the review thing at the booklet.