Monday, October 19, 2015

Continuity:
f(x)= {-3+x,    x<-4  
         {x^-2,       -4<x<2
         {x+1,      x>2

Step 1: x--> -4-     (-3+(-4))  = -7
            x--> -4+    (-4^2 - 2 = 14
The function is not continuous because it does not come together at x=-4 from the left and right sides.

Intermediate Value Theorem: f(x)= x^2-2x - 3  on [2,6]
f(2) = -3
f(6) = 21
The IVT allows us to say that along the interval [2,6] there is a solution N.

f(x)= x^2 + 4x -22 on [1,3]
f(1)= -17
f(3)= -1
The IVT doesn't prove that there is a solution along the interval [2,6]

Derivatives: Two types of derivatives.

One way to solve: f(x) - f(a)
                         ----------------
 x-->a                        x-a


Second Way to Solve: Difference Quotient  f(x+h) -f(x)
                                                             -----------------
                                                                      h                  h--> 0

Ex: f(x) = 3x+7


3(x+h) +7 -(3x+7)
----------------------     h --> 0        
             h

3x+3h +7 -3x - 7          h(3x+3 + 7 -3x -7
--------------------  -->                                  
            h
x=3 The slope of the function as a whole (derivative) is 3.


Instantaneous vs Average Velocity: Instantaneous Velocity is slope at one certain point. Average Velocity is the average slope over an equation as a hole.



2 comments:

  1. The first piecewise could be continuous at 2, be sure to check that

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  2. "it does not come together" could read "the limit does not exist at x = 2, since the limit from the left is not the same as the limit from the right" so that you sound more scholarly. No "hole" at the end - "whole".
    You did not answer the question "What is the hardest part of finding a derivative for you?"

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