Question:

If $I(x)=\int x^{2}(\log x)^{2} d x$ and $I( 1)=0$, then $I(x)$

Updated On: Jun 9, 2023
  • $\frac{x^{3}}{18} \left[ 8\left(\log x\right)^{2} -3\log x\right] + \frac{7}{18} $
  • $\frac{x^{3}}{27} \left[9\left(\log x\right)^{2} +6 \log x\right] - \frac{2}{27} $
  • $\frac{x^{3}}{27} \left[9\left(\log x\right)^{2} - 6 \log x+2\right]- \frac{2}{27} $
  • $\frac{x^{3}}{27} \left[9 \left(\log x\right)^{2} -6 \log x +2 \right] - \frac{2}{27}$
Hide Solution
collegedunia
Verified By Collegedunia

The Correct Option is C

Solution and Explanation

Given integral $I(x)=\int x^{2}(\log x)^{2} d x= \frac{x^{3}}{3}(\log x)^{2}-\int \frac{x^{3}}{3} \frac{2 \log x}{x} d x$ [by integration by parts] $= \frac{x^{3}}{3}(\log x)^{2}-\frac{2}{3}\left[\frac{x^{3}}{3}(\log x)-\int \frac{x^{3}}{3}\left(\frac{1}{x}\right) d x\right]$ $= \frac{x^{3}}{3}(\log x)^{2}-\frac{2}{3}\left[\frac{x^{3}}{3}(\log x)-\frac{1}{3} \frac{x^{3}}{3}\right]+C$ $=\frac{x^{3}}{27}\left[9(\log x)^{2}-6(\log x)+2\right]+C$ $\because I(1)=0$ $\therefore \frac{2}{27}+C=0$ $\Rightarrow C=-\frac{2}{27}$ $\therefore I(x)=\frac{x^{3}}{27}\left[9(\log x)^{2}-6(\log x)+2\right]-\frac{2}{27}$
Was this answer helpful?
1
0

Questions Asked in AP ECET exam

View More Questions

Concepts Used:

Integral

The representation of the area of a region under a curve is called to be as integral. The actual value of an integral can be acquired (approximately) by drawing rectangles.

  • The definite integral of a function can be shown as the area of the region bounded by its graph of the given function between two points in the line.
  • The area of a region is found by splitting it into thin vertical rectangles and applying the lower and the upper limits, the area of the region is summarized.
  • An integral of a function over an interval on which the integral is described.

Also, F(x) is known to be a Newton-Leibnitz integral or antiderivative or primitive of a function f(x) on an interval I.

F'(x) = f(x)

For every value of x = I.

Types of Integrals:

Integral calculus helps to resolve two major types of problems:

  1. The problem of getting a function if its derivative is given.
  2. The problem of getting the area bounded by the graph of a function under given situations.