The correct answer is (D) : 20(π+2)
\(\int_{0}^{20\pi} (|\sin x| + |\cos x|)^2 \,dx\)
\(20 \int_{0}^{\pi} (1 + |\sin(2x)|) \,dx\)
\(40 \int_{0}^{\frac{\pi}{2}} (1 + \sin(2x)) \,dx\)
\(40 \left( x - \frac{\cos(2x)}{2} \right) \Bigg|_{0}^{\frac{\pi}{2}}\)
\(= 40(\frac{\pi}{2}+\frac{1}{2}+\frac{1}{2})\)
\(= 20(\pi +2)\)
The value \( 9 \int_{0}^{9} \left\lfloor \frac{10x}{x+1} \right\rfloor \, dx \), where \( \left\lfloor t \right\rfloor \) denotes the greatest integer less than or equal to \( t \), is ________.
A thin uniform rod (\(X\)) of mass \(M\) and length \(L\) is pivoted at a height \( \left(\dfrac{L}{3}\right) \) as shown in the figure. The rod is allowed to fall from a vertical position and lie horizontally on the table. The angular velocity of this rod when it hits the table top is ________. (\(g\) = gravitational acceleration) 
If $\cot x=\dfrac{5}{12}$ for some $x\in(\pi,\tfrac{3\pi}{2})$, then \[ \sin 7x\left(\cos \frac{13x}{2}+\sin \frac{13x}{2}\right) +\cos 7x\left(\cos \frac{13x}{2}-\sin \frac{13x}{2}\right) \] is equal to
Definite integral is an operation on functions which approximates the sum of the values (of the function) weighted by the length (or measure) of the intervals for which the function takes that value.
Definite integrals - Important Formulae Handbook
A real valued function being evaluated (integrated) over the closed interval [a, b] is written as :
\(\int_{a}^{b}f(x)dx\)
Definite integrals have a lot of applications. Its main application is that it is used to find out the area under the curve of a function, as shown below:
