Writing and interpreting exponential functions

The equation y = 210(1.094)^x depicts the amount of money in a savings account after x years. What does the y-intercept represent in the equation?

• the growth factor of the account

• the initial amount of the account

• the maximum amount of the account

• the minimum amount of the account

• 1
• 0.98
• 2
• right
• 8000
• 3
• left
• percent
• decimal

• 300

• 1.05

• x

What is the starting amount in the problem below?

f(t) = 300(1.05)^t

• 300

• 1.05

• t

• y

• Amount of money we have after t years

• 2

• The initial investment amount

• 1,000

• time needed to double once (72/%)

• 9

• time in years

• t

• The growth factor

• A(t)

• $320
• decreases
• 10%
• $288
• $352
• increases
• 90%
• 110%

Two students were infected by chicken pox today. The number of infected students are a function of the number of days, x. The number of infected students, after each day, x, is given by the function A(x) = 2(3)^x. What does A(6) = 1,458 mean in the context of the problem?

• When 6 days have passed, 1,458 students have been infected with the chicken pox.

• When 1,458 days have passed, 6 students have been infected with the chicken pox

• 2 students have the chicken pox

 $y=-1.5\left(3\right)^x$  What's the y-intercept of the function?

• -1.5

• 3

• 1.5

• x

What does the y-intercept represent in the word problem?

• The number of bounces the basketball takes

• The height of the basketball after the first bounce

• The original height of the basketball

• The rate at which the basketball bounces

Q = 3.1(0.78)^t

What is the initial quantity?