What is the rate of change for the formula y = 5x + 10y=5x+10 over the interval [0, 4][0,4]?

1 Answer
Feb 6, 2018

See a solution process below:

Explanation:

The formal for the average rate of change over a closed interval [a, b][a,b] is:

(f(b) - f(a))/(b - a)f(b)f(a)ba

So for this problem the interval is: [0, 4][0,4]

And

f(4) = y_b = (5 xx 4) + 10 = 20 + 10 = 30f(4)=yb=(5×4)+10=20+10=30

f(0) = y_a = (5 xx 0) + 10 = 0 + 10 = 10f(0)=ya=(5×0)+10=0+10=10

Substituting this into the formula gives:

(f(b) - f(a))/(b - a) = (30 - 10)/(4 - 0) = 20/4 = 5f(b)f(a)ba=301040=204=5

For a linear equation the rate of change over any interval is the slope which for this equation is also 55.