Q. What is the average value of 6x2+8 on the interval [3,5] ?
Calculate Interval Width: To find the average value of a function f(x) on the interval [a,b], we use the formula:Average value = (1/(b−a))×∫abf(x)dxHere, f(x)=6x2+8, a=3, and b=5.
Set Up Integral: First, we calculate b−a, which is the width of the interval.b−a=5−3=2
Find Antiderivative: Next, we set up the integral of the function f(x) from 3 to 5. ∫35(6x2+8)dx
Evaluate Antiderivative: We need to find the antiderivative of f(x). The antiderivative of 6x2 is 6×(3x3) and the antiderivative of 8 is 8x.Antiderivative of f(x) = 6×(3x3)+8xSimplify the antiderivative: 2x3+8x
Subtract Values: Now we evaluate the antiderivative at the upper and lower limits of the interval and subtract.Plug in x=5: 2∗(5)3+8∗(5)=2∗125+40=250+40=290Plug in x=3: 2∗(3)3+8∗(3)=2∗27+24=54+24=78
Divide for Average: Subtract the value of the antiderivative at x=3 from the value at x=5.290−78=212
Divide for Average: Subtract the value of the antiderivative at x=3 from the value at x=5.290−78=212Finally, we divide the result by the width of the interval to find the average value.Average value=(21)∗212=106
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