Exponential Functions and Interest

Which among the following topics can be represented by the exponential function?

• decaying of medicine

• loan

• simple interest

• participants in research

Which of the following didn’t shows an exponential decay?

• f(x) = 5 ^{- x}

• g(x) = ½ ^x

• h(x) = 0.67 ^x

• y = 1.75 ^x

The following are representation of exponential function except______.

• The speed of a car in a highway

• The population growth in a City within 100 years.

• Manny deposits money in the bank that is compounded annually.

• Mikael invests in a business where her profit earning a 20% simple interest annually.

A substance of 50 grams reduce 1/5 of its weight every minute. How heavy will it be after 5 minutes. Represent the problem into exponential form.

• y = 50 (1/5)⁵

• y = 50(5) ^t/5

• y = 50(1/5) ^5/T

• y = 5(1/5) ⁵⁰

The following are exponential expressions except.

• 3 ^2x < 27

• f(x)=2 ^x −3x+4

• 2 ^{3 x −4} = 16

• f(x)=2 ^x −64

What will happen to the inequality symbol when the base is 0 < α < 1?

• retains

• reverse

• inverse

• change to equal

Solve: (½) ^x = 8

• x = -3

• x = -2

• x = 2

• x = 3

Solve 9 ^8-x =27 ^x-3 ?

• x=5

• x=-5

• x=1/5

• x=-1/5

What are the values of x that satisfy the inequality 5 ^3x-1 > 25?

• (-∞,1)

• (1,∞)

• (-∞,∞)

• ℝ

Evaluate the function f(x) = 5 ^x - 10 when x = 3.

• 5

• 54

• 115

• 125