WARM UP-do not write on the white description sheets

--TAKE A SHEET OF PAPER, A NOTE CARD FROM THE

STOOL, TAKE OUT COLOR PENCILS FROM THE BOX

BELOW YOUR SEAT(pick out one pencil you would like to use)

AND READ SILENTLY.

WARM UP

Create a bioand include thefollowing

Best Attribute:

Appearance:

Hidden Talent:

Shortcomings:

Quote:

Section 9-7: Exponential Growth &

Decay

04/21/23 Section 8-8

Growth vs. Decay

Growth

Increase

Investment

Grows

Appreciates

Decay

Decreases

Depreciates

Half Life

04/21/23 Section 8-8

Exponential Growth

y = a ∙ (1 + r)x

initial amount (when x = 0)

growth factor (expressed as a decimal)

time frame (days, months,

years, etc.)

04/21/23 Section 8-8

Growth and Decay

If the number in the parenthesis is greater than 1, it is exponential growth Example: y = 3(1.7)t

If the number in the parenthesis is less than 1, it is exponential decay. Example: y = 2(0.5)t

04/21/23 Section 8-8

y = a ∙ (1 + r )x

You have a Visa card with a balance of $1,500. Visa is charging you an interest rate of 1.5 % per month. How much will you owe after one year? (Assuming you make no payments).

04/21/23 Section 8-8

Your turn

The student population at Topsail High School is growing by 5% per year. If the current student body is 920 students, what is the predicted population in 3 years when you graduate?

04/21/23 Section 8-8

One more time…

Compound interest:

Your parents deposited $1500 in an account paying 6.5% annual interest compounded annually when you were born. Find the account balance after 18 years.

How much would be in the account if the interest was compounded quarterly?

04/21/23 Section 8-8

y = a ∙ (1 – r)x

Half-life:

The half-life of iodine-124 is 4 days. A technician measures a 40-mCi sample of iodine-124.

a) How much iodine-124 is left in the sample after 4 days?

b) How many half-lives occur in 16 days?

c) How much iodine-124 is left in the sample after 16 days?

04/21/23 Section 8-8

Your turn

You buy a used car for $18,000. The car loses 12% of its value each year due to depreciation. Find the value of the car after 5 years & 10 years.