Log and Exponential Function

Change y = a^x into log form.

• x = log_ay

• y = log_ax

• x = log_ya

• y = log a

A new savings account is opened with $400 and gains 3% every year. What is the exponential function?

• f(x)=400(.97)^x

• f(x)=400(1-0.03)^x

• f(x)=400(1.03)^x

• f(x)=400(0.03)^x

The value of a car is $15,000 and depreciates at a rate of 8% per year. What is the exponential equation?

• y=8(15,000)^x

• y=15,000(1.08)^x

• y=15,000(0.92)^x

• y=15,000(0.08)^x

The original value of a painting is $1400, and the value increases by 9% each year. Write an exponential growth function to model this situation.

• y=1400(1.09)^x

• y=1.09(1400)^x

• y=1400(.91)^x

• y=1.09^x

Suppose a culture of bacteria begins with 5000 cells and dies by 30% each year. Write an equation that represents this situation.

• y=5000(0.7)^x

• y=30(5000)^x

• y=5000(1.3)^x

• y=5000x^x

Write an equation that models the following situation:
Samantha's hair was known to grow very rapidly. It began at a length of 6 in and grew at a rate of 14% a week.

• y=6(0.14)^x

• y=6(1+14)^x

• y=6(1.14)^x

• y=6(0.86)^x

Match the graph with its equation

• y = log₅ (x + 1) + 1 

• y = log₅ (x - 1) + 1 

• y = log₅ (x²) + 1 

• y = log₅ (x)-1

Match the graph with its equation

• y = log₄ (x)+2

• y = log₄ (x + 2) + 1 

• y = log₄ (x - 1) + 2

• y = log₄ (-x + 2)

Match the graph with its equation

• y = log₆(-x) + 1

• y = log₆(x − 2) + 1

• y = log₆(x + 2) - 1

• y = log(x-8) + 1

Which graph matches the equation?

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