One spring, Mr. Gambrill felt as if he needed to mow his lawn particularly often. So after a mowing, he measured the height of his grass. He continued to measure it each day until the next mowing. The equation below represents the relationship between time, x, in days and height of the grass, y, in centimeters. What was the rate of change for the growth of Mr. Grambrill's grass?

Y=6+1.5x

1.5 cm/day

4 cm/day

4.5 cm/day

6 cm/day

Question

One spring, Mr. Gambrill felt as if he needed to mow his lawn particularly often. So after a mowing, he measured the height of his grass. He continued to measure it each day until the next mowing. The equation below represents the relationship between time, x, in days and height of the grass, y, in centimeters. What was the rate of change for the growth of Mr. Grambrill's grass? 


Y=6+1.5x




1.5 cm/day

 4 cm/day

 4.5 cm/day

 6 cm/day

aaronq · Answer

The rate of change is 1.5 cm/day

this is because 6 cm is the baseline height, the change is 1.5x

you could also see that the first derivative of the equation is f'(x)=1.5; the first derivative is the slope of the f(x) vs time graph (in this case).