Material on derivatives since first exam (e.g., chain rule,
implicit differentiation, related rates, extreme values, Mean
Value Theorem, optimization, etc.)
Rules and format similar to first hour exam
Including open book, notes, references
But probably slightly more questions (7 - 9), and slightly
harder questions e.g., more word problems
Questions?
Optimization
Section 4.5
Optimization often about finding minimum or maximum values
How to solve optimization problems
Read problem
Draw picture
Introduce variables
Write equation
Test critical points & endpoints in derivative
Examples, e.g.,
Fermat’s principle: light travels on minimum-time paths
Snell’s law follows from this: sinΘ1 / c1 = sinΘ2 / c2
Examples
Radios, televisions, etc. are tuned to a particular station by an
electrical circuit whose resistance (R) depends on the
frequency (f) of the radio wave according to the formula
R = (Lf) / (1 + LCf2)
Where L and C are parameters of the tuner (and hide some
constants of proportionality in some versions of the formula).
What is the frequency at which resistance is highest for fixed
L and C (that’s the frequency the radio/televions/etc
is receiving)?
How to start? find dR/df
Set dR/df = 0, solve for f
Do manufacturers of buckets actually use dimensions that
come close to minimizing the amount of material needed to
make the bucket?
Bucket = cylinder w/ one end closed
Cost modelled by area
Even though volume of plastic = surface area times thickness