Algebra - Functions Review

Which most likely describes a situation in which the graph is continuous?

• On average 145 students are absent each day

• A dentist sees 40 patients a week

• The amount of water pouring out of a hose over time.

• One tree is planted for every $5 donated

Answer explanation

Since the water continuously pours out of the hose, the domain can be broken down into infinitely small parts. This makes it reasonable for the graph to be continous.

Which set of points shows an undefined slope?

• None of these

Answer explanation

Since the slope his the rise over the run, if the run (change in x) is 0, the slope will be undefined.

• A geometric function

• An arithmetic function

• A quadratic function

• None of these

Answer explanation

When the input variable is an exponent and the base is a constant, you get a geometric (also called an exponential) function.

Marcus deposits $1250 into an account that will earn 6% interest each year. He gets interest at the end of each year, but not inbetween.

• This graph would be geometric and discrete

• This graph would be linear and discrete

• This graph would be geometric and continuous

• This graph would be linear and continuous

Answer explanation

Situations that describe growth based on a percent are geometric. Since interest only happens once each year the graph would have distinct, separate points, making it descrete.

Marcus deposits $1250 in an account that will earn 6% interest each year. Which equation is the best explicit equation to use to find the amount of money that Marcus will have in his account at any year in the future?

Answer explanation

On a percent increase problem, you add the percent in the problem to 100 percent to get the common ratio. The ratio must be written as a decimal.

Kylie buys a new car with a beginning value of $24,000. The dealer told her to expect the car to depreciate (go down in value) by 8% per year. To the nearest whole dollar, what is her car worth after 2 years?

• $22,080

• $27,994

• $20,160

• $20,314

Answer explanation

Since the car is going down in value the common ratio will be based on 100 percent minus 8 percent. Use .92 as your common ratio.

• None of these

Answer explanation

Plug the 4 in for the x.

-4(4)+3 equals -16+3 for a final value of -13.

Find the slope between the points (5,-6) and (-1, 8). Simplify your final answer.

Answer explanation

Remember to subtract your y values for the numerator (top) of the fraction. Be careful about those negatives too!

Find the missing number on the table so that it will represent points from a linear function.

• 16

• 22

• 14

• None of these

What is the explicit equation for the arithmetic sequence in the table?

Answer explanation

Since this is arithmetic the common difference is multiplied by the x. You also need to work backwards to the beginning term (the zero step) for the equation.

Tags

CCSS.HSF.BF.A.2