Sunday, February 21, 2010

Post #27

So, these holidays zoomed by..umm, this time i'll explain some frequently missed things..

For one, i'll explain the chain rules.

cos(4x^2)

you have to start with the outtermost first, then innermost..

so take the derivative of cos, which is -sin, and then the derivative of the inside quantity, 4x^2, 8x

= -sin(8x)

Now, lets review some limit rules.

WHEN THE LIMIT IS APPROACHING INFINITY:

top degree < bottom degree = zero

top degree > bottom degree = positive or negative infinity

top degree = bottom degree = divided coefficiants

WHEN THE LIMIT IS APPROACHING A NUMBER:

1. factor out the top and bottom

2. look for cancellations

3. plug in the number

Hopefully this was a good review for everyone..its seems to the the things i commonly miss..

1 comment:

  1. I think I need to print this out or tattoo it to my forehead.
    it was plain and simple English and I applaud you!!
    I especially needed the help with the chain rule, but what if you have say + or - or X terms?

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