Common Core: 8th Grade Math : Functions

Study concepts, example questions & explanations for Common Core: 8th Grade Math

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Example Questions

Example Question #9 : Describe Qualitatively The Functional Relationship Between Two Quantities By Analyzing A Graph: Ccss.Math.Content.8.F.B.5

The graph provided displays the speed of a race car during a race. 

3

Based on the graph, what is likely occurring in the first  of the race?  

Possible Answers:

The race car driver is driving at a consistent speed 

The race car driver is waiting to begin the race

The race car driver is decreasing his speed

The race car driver is increasing his speed

Correct answer:

The race car driver is increasing his speed

Explanation:

The time is displayed along the x-axis of the provided graph. During the first  of the race, the driver goes from , displayed on the y-axis of the graph, to . We can see the line between those two points is increasing in a positive direction, or getting faster; thus, the race car driver is increasing his speed. 

Example Question #10 : Describe Qualitatively The Functional Relationship Between Two Quantities By Analyzing A Graph: Ccss.Math.Content.8.F.B.5

The graph provided displays the speed of a race car during a race. 

2

Based on the graph, what is likely occurred between the  and  part of the race? 

Possible Answers:

The race car driver stopped

The race car driver finished the race

The race car driver slowed down

The race car driver increased his speed

Correct answer:

The race car driver slowed down

Explanation:

Between the  and  part of the race, the race car driver decreases his speed from  to . If we look pasted this point on the graph, we see that he speeds back up and continue with the race, so the race didn't not end. He also didn't stop, because his speed never hit ; thus, he must have had to slow down for some reason, but then resumed the race.

Example Question #11 : Describe Qualitatively The Functional Relationship Between Two Quantities By Analyzing A Graph: Ccss.Math.Content.8.F.B.5

The graph provided displays the speed of a race car during a race. 

3

Based on the graph, what is likely occurred between the  and  part of the race? 

Possible Answers:

The race car driver is waiting to begin the race

The race car driver is driving at a consistent speed 

The race car driver is decreasing his speed

The race car driver is increasing his speed

Correct answer:

The race car driver is driving at a consistent speed 

Explanation:

The time is displayed along the x-axis of the provided graph. Between the   and  part of the race, the driver is going  at each time point. We can see from the straight line between those two points that the race car driver's speed doesn't change; thus, the race car driver is driving at a consistent speed.

Example Question #71 : Functions

The graph provided displays the speed of a race car during a race. Based on the graph, what is likely occurring between the  and  part of the race? 

3

 

Possible Answers:

The race car driver is waiting to begin the race

The race car driver stopped for some reason

The race car driver finished the race

The race car driver increased his speed

Correct answer:

The race car driver stopped for some reason

Explanation:

Between the  and  part of the race, the race car driver decreases his speed from  to . If we look pasted this point on the graph, we see that he speeds back up and continue with the race, so the race didn't not end. Because he comes to a stop at , he didn't just slow down, he stopped; thus, he must have had to stop for some reason, but then resumed the race. 

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