Rapid Recall

1. If we know $x=2u+3v$ and $y=4u+5v$, then $dA_{xy} = ? dudv$.

Solution

Note that $dx = 2du+3dv$ and $dy=4du+5dv$. We can write this as $$(dx,dy)=(2,4)du+(3,5)dv.$$ The area of the parallelogram formed by the two vectors above is $A=|2\cdot 5-3\cdot 4|=2$.

2. Draw the curve $r = 3+2\cos\theta$.

3. Set up an integral that finds the area that lies inside the curve $r = 6+3\cos\theta$ and outside a circle of radius 3.

Solution

Group problems

  1. Draw the region in the $xy$ plane described by $0\leq \theta \leq \pi/3$ and $0\leq r\leq 2\sin3\theta$.
  2. Draw the region in the $xy$ plane described by $0\leq \theta \leq \pi/4$ and $0\leq r\leq 3\sin2\theta$.
  3. Set up a double integral that gives the area of the region in the $xy$ plane that lies inside one petal of the rose $r=3\cos2\theta$.
  4. Draw and shade the region in the $xy$ plane that lies inside the curve $r=3+2\cos\theta$ and outside the curve $r=1$.
  5. Set up a double integral that gives the area of the region in the $xy$ plane that lies inside the curve $r=3+2\cos\theta$ and outside the curve $r=1$.
  6. Set up a double integral that gives the area of the region in the $xy$ plane that lies inside the curve $r=2-2\cos\theta$ and inside the curve $r=2\cos\theta$.
  7. Set up a double integral that gives the area of the region in the $xy$ plane that lies inside the curve $r=2-2\cos\theta$ and outside the curve $r=2\cos\theta$.

Problem Set
Today

« October 2019 »

Sun

Mon

Tue

Wed

Thu

Fri

Sat

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31