11.7 Day 2 Spherical coordinatesFor an animation of this topic visit:

http://www.math.umn.edu/~nykamp/m2374/readings/sphcoord/

A Calculator to graph spherical coordinates:http://cs.jsu.edu/mcis/faculty/leathrum/Mathlets/awl/spherical-main.html

For an animation of spherical coordinates visit:

http://www.math.umn.edu/~nykamp/m2374/readings/sphcoord/

The Spherical Coordinate System

Conversions between Spherical and other Coordinate systems

Please record these in your notes

__

You do not need to memorize the following formulas but will need to be able to apply them

Spherical coordinates

r (due to opposite sides of a parallelogram)

Spherical coordinates

Cosφ = z/ρρ Cosφ = z

sin φ =r/ ρ

r = ρ sin φ (save this result)

Cosθ = x/r

Cosθ = x/(ρ sin φ )

X= ρ sin φ Cosθ

tanθ = y/x

tanθ = y/( ρ sin φ Cosθ) (from previous slide)

tanθ (ρ sin φ Cosθ) = y

sin θ (ρ sin φ Cosθ) =yCosθ

y = ρ sin φ sin θ

Converting between coordinate systems

Example 5a

Find an equation in spherical coordinates for the surface represented by the rectangular equation.

Solution to example 5aCone: x2 + y 2 = z2

Example 5 b

Find an equation in spherical coordinates for the surface represented by the rectangular equation.

Solution to 5b

Common equations in spherical coordinates

Converting between coordinate systems

Do examples from text book

P. 825 # 58,76,

(76 is shown on the next slide_

76

cylindrical

Changing between coordinates on the TI 89

Press 2nd 5 (math) – 4 matrices – L Vecor opsto sphereTo convert rectangular to Polar (2 D)[1,2,3] to sphere (to is expressed with a triangle)

Note: You can change from rectangular to polar, cylindrical or spherical

Or change from polar to rectangular with built in functions

One use of spherical coordinates:

Image: Bosch 36W column loudspeaker polar pattern

For more information visit:http://en.wikipedia.org/wiki/Polar_coordinates

A math sing along

• ρρρ …

Row, Row, Row your boat …

By Mr. Whitehead