Q. Find the average value of the function f(x)=x−11 from x=5 to x=9. Express your answer as a constant times ln2.Answer: □ln2
Average Value Formula: To find the average value of a continuous function f(x) on the interval [a,b], we use the formula for the average value of a function on an interval, which is given by:Average value = (b−a)1∫abf(x)dxHere, f(x)=(x−1)1, a=5, and b=9.
Calculate Integral: First, we calculate the integral of f(x)=x−11 from x=5 to x=9.∫59(x−11)dxThis is a standard integral that can be solved by recognizing it as the integral of u1 where u=x−1.Let u=x−1, then du=dx.
Apply u-Substitution: Change the limits of integration to match the u-substitution.When x=5, u=5−1=4.When x=9, u=9−1=8.Now we integrate with respect to u from u=4 to u=8.∫48(u1)du
Evaluate Integral: The integral of u1 with respect to u is ln∣u∣. So we evaluate ln∣u∣ from u=4 to u=8. ln∣u∣ evaluated from 4 to 8 is ln∣8∣−ln∣4∣.
Simplify Natural Log: We know that ln∣8∣ is ln(23) which is 3ln(2), and ln∣4∣ is ln(22) which is 2ln(2). So, ln∣8∣−ln∣4∣=3ln(2)−2ln(2)=ln(2).
Multiply by Factor: Now we have the integral result, which is ln(2). We need to multiply this by the factor (1/(b−a)) to find the average value.(1/(9−5))×ln(2)=(1/4)×ln(2).
Final Answer: Simplify the expression to get the final answer.(41)×ln(2)=0.25ln(2).
More problems from Find the roots of factored polynomials