“ARE U Planning for Next
Summer / Modeling Cardiovascular Dynamics During Blood Withdrawal”
REU programs and the work of one particular one
Jacob Goldberg, Geneseo Math major
Wednesday, Oct. 21, 2:45, Newton 202
Extra credit as usual (but connections need to be more than
“I want to do an REU”)
Please cancel appointments you can’t keep as early as possible
Questions Not Answered Last Time
Is there an analog of L’Hôpital’s Rule for
multi-variable functions? Probably not, although it might be
possible in certain special cases (e.g., function can be
parameterized in a way that makes it a single-variable function)
Demonstrate a function for which the mixed derivative theorem
doesn’t hold? Harder than it seems, theorem in book actually
puts more restrictions on the function and its derivatives than necessary
Questions?
Level curves?
f(x,y) = k defines implicit equation that relates x and y
So use implicit curve plotter to draw it
e.g., muPad plot::Implicit2d
The Chain Rule for Partial Derivatives
Section 14.4
Chain rule feels optional, especially when x, y are functions of 1 variable
But lets you isolate components
Branch diagrams helpful
Examples
Find dw/dt if w = xy, x = t2, y = 2t
Find ∂w/∂u and ∂w/∂v if w = xey, x = uv, y = u lnv