9:00 AM Jamboard Links

G1 G2 G3 G4 G5 G6 G7
  • Kallan DuPaix
  • Spencer Hatch
  • Zack Kunkel
  • Marissa Mavy
  • Santiago Meza Jr
  • Spencer Blau
  • Jordan Cluff
  • Ryan Cox
  • Makenzy Pharis
  • Gavin Slater
  • Ethan Barrus
  • Rachel Hardy
  • Parker Kemp
  • Denali Russell
  • Cecilia Sanders
  • Jeremy Boyce
  • Karen Castillo Avendano
  • Mason Peterson
  • Luke Romeril
  • Nathan Thompson
  • Kylar Dominguez Pluma
  • Logan Grover
  • Tanner Harding
  • Olivia Houghton
  • Jae Kim
  • Kai Alger
  • Nathan Bryans
  • Lucy Fisher
  • Chase Fry
  • Braydon Robinson
  • Evan Duker
  • Ralph Oliver
  • Tyler Stokes

12:45 PM Jamboard Links

G1 G2 G3 G4 G5 G6
  • Adam Hopkins
  • Oscar Enrique Gonzalez Mosqueda
  • Reed Hunsaker
  • Rick Miller
  • Trevor Fike
  • Forrest Thompson
  • Hamilton Birkeland
  • Jeremy Jacobsen
  • Michael Clarke
  • Adrick Checketts
  • Alan Loureiro
  • Christian Shamo
  • Preston Yost
  • Carter Cooper
  • Chad Larkin
  • Joshua Strang
  • Michael Ruiz
  • Brian Odhiambo
  • Cheyenne Pratt
  • Jacob Gravelle
  • Matty Davis
  • Aaron Reed
  • Brad Johnston
  • Hayley Kerkman
  • Jaden Camargo
  • Tanner Anderson

Presenters

9AM

Thanks for sharing things in Perusall. Here are the presenters for today.

  • 3.6 - Luke
  • 3.7 - Ryan, Chase
  • 3.8 - Makenzy
  • 3.9 - Olivia
  • 3.10 - Ethan
  • 3.11 - Spencer B
  • 3.12 - Tanner
  • 3.13 - Gavin

12:45PM

Thanks for sharing things in Perusall. Here are the presenters for today.

  • 3.6 - Aaron R
  • 3.7 - Oscar
  • 3.8 - Alan
  • 3.9 - Forrest
  • 3.10 - Trevor
  • 3.11 - Nicholas B
  • 3.12 -
  • 3.13 -

Learning Reminders

  • We are in the 13th week of the semester. If you are on track for an A, then ideally you're finishing your SDL project for the 5th unit, and proposed something for the 6th unit.
  • There are only 2 weeks left, which means you can submit at most 2 more SDL projects.
  • The final SDL project (6th) can be over any topic from the entire semester. You can use it to expand what we do in the 6th unit, or you may choose to revisit something from a prior unit that you would like to spend more time with.

Rapid Recall

  • We know $x=r\cos\theta$. For the curve $r=2\sin\theta$, find $\ds \frac{dr}{d\theta}$ and $\ds \frac{dx}{d\theta}$.

Solution

We have $\frac{dr}{d\theta} = 2\cos\theta$ and $x=(2\sin\theta)(\cos\theta)$, which means $$\begin{align} \frac{dx}{d\theta}&= (2\sin\theta)'(\cos\theta)+(2\sin\theta)(\cos\theta)'\\ &= (2\cos\theta)(\cos\theta)+(2\sin\theta)(-\sin\theta). \end{align}$$

  • For the change of coordinates $x=2u+3v^2$ and $y=4u^3+5v$, write the differential $(dx,dy)$ in the form

$$ \begin{pmatrix}dx\\dy\end{pmatrix}= \begin{pmatrix}?\\?\end{pmatrix}du+ \begin{pmatrix}?\\?\end{pmatrix}dv.$$

Solution

First, note that $$\begin{align} dx&=2du+6vdv\\ dy&=12u^2du+5dv. \end{align}$$ Rewriting this in vector form gives $$ \begin{pmatrix}dx\\dy\end{pmatrix}= \begin{pmatrix}2\\12u^2\end{pmatrix}du+ \begin{pmatrix}6v\\5\end{pmatrix}dv. $$

  • For the curve $r=2+2\sin\theta$, graph the curve in the $r\theta$ plane.

Solution

Here is a Desmos Graph.

  • For the curve $r=2+2\sin\theta$, graph the curve in the $xy$ plane.

Solution

Here is a Desmos Graph.

Group problems

  1. Review: for the equation $z=x^2y+3y^2$, briefly discuss why $\ds\frac{dz}{dt} = 2xy\frac{dx}{dt}+x^2\frac{dy}{dt}+6y\frac{dy}{dt}$.
  2. Compute the differential $dA$ for the area function $A=xy$.
  3. We know $x=r\cos\theta$. Explain why $dx = \cos\theta dr-r\sin\theta d\theta$.
  4. We know $y=r\sin\theta$. Compute $dy$ in terms of $r,\theta,dr,d\theta$.
  5. Plot the curve $r=3-3\sin\theta$ in the $r\theta$ plane, and then in the $xy$-plane. [Hint: Make an $(r,\theta)$ table, but pick values for $\theta$ that make $\cos\theta$ easy to compute. Did you get a heart shaped object?]
  6. Plot the curve $r=3\cos2\theta$ in the $r\theta$ plane, and then in the $xy$-plane. [Hint: Make an $(r,\theta)$ table, but pick values for $\theta$ that make $\sin2\theta$ easy to compute (multiples of 45 degrees). Did you get a clover?]
  7. Plot the curve $r=4-4\cos\theta$ in both the $r\theta$-plane, and the $xy$-plane.
  8. Plot the curve $r=3\sin2\theta$ in both the $r\theta$-plane, and the $xy$-plane.

Problem Set
Today

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