Workbook pg. 231

#1-22 (skip 15 &19)

Monday October 8

Daily Check:Chords

Daily Check1. 2.

3. 4.

D

Describe the extrema of the quadratic y = -2(x – 3)2 + 2

a. Maximum at (-3, 2)

b. Minimum at (-3, 2)

c. Minimum at (3, 2)

d. Maximum at (3, 2)

r

HEMISPHERE: HALF A SPHERE

Think of the globe!

The equator cuts the earth into the northern and southern hemisphere.

Formulas for a Sphere2

3

4

4

32

SA r

V r

C r

10 cm

Find the exact and approximate Surface Area & Volume of a Sphere (round to the nearest hundredths)

216.314100 cmSA 3500

523.60 cm3

V

25 in

The circumference of a great circle of a sphere is 25 inches. Find the approximate surface area & volume of the sphere. (Round to the nearest tenths.)

3.979r 2198.96SA in

3263.88 inV

5 in

SA and Volume of a SphereA spherical balloon has a surface area of 16 in.2 Find the volume of the sphere.

36.02 inV

10 in

34

3V rSA4 r2

5 in

Surface Area & Volume of a SphereA spherical balloon has an initial radius of 5 in. When more air is added, the radius becomes 10 in. Explain how S.A. and Volume change as the radius changes.

10 in

is 8 times biggerV is 4 times biggerSA

Old Sphere New Sphere

Radius

Surface Area

Volume

If radius is doubled…

x 2

x 22

x 23

Old Sphere New Sphere

Radius

Surface Area

Volume

If radius is 5 times bigger…

x 5

x 52

x 53

Old Sphere New Sphere

Radius

Surface Area

Volume

If radius is 2/3 smaller…

x 2/3

x (2/3)2

x (2/3)3

5 in

Volume of a SphereA sphere has an initial volume of 400 cm.3 The sphere is made bigger by making the radius 4 times as big. What is the new volume of the sphere?

325,600 inV

10 in

34

3V r