Evaluate a definite integral or solve for unknowns by exploiting functional equations, symmetry (e.g., f(x) + f(a−x) relations), or clever substitutions that simplify the integrand.
Let $F ( x ) = f ( x ) + f \left( \frac { 1 } { x } \right)$, where $f ( x ) = \int _ { 1 } ^ { x } \frac { \log t } { 1 + t } d t$. Then $F ( e )$ equals (1) $\frac { 1 } { 2 }$ (2) 0 (3) 1 (4) 2
Statement-I: The value of the integral $\int_{\pi/6}^{\pi/3} \frac{dx}{1 + \sqrt{\tan x}}$ is equal to $\frac{\pi}{6}$. Statement-II: $\int_a^b f(x)\, dx = \int_a^b f(a + b - x)\, dx$. (1) Statement-I is true; Statement-II is false. (2) Statement-I is false; Statement-II is true. (3) Statement-I is true; Statement-II is true; Statement-II is a correct explanation for Statement-I. (4) Statement-I is true; Statement-II is true; Statement-II is not a correct explanation for Statement-I.
The value of the integral $\int _ { 4 } ^ { 10 } \frac { \left[ x ^ { 2 } \right] } { \left[ x ^ { 2 } - 28 x + 196 \right] + \left[ x ^ { 2 } \right] } d x$, where $[ x ]$ denotes the greatest integer less than or equal to $x$, is (1) $\frac { 1 } { 3 }$ (2) 6 (3) 7 (4) 3
If $f(x) = \frac{2 - x\cos x}{2 + x\cos x}$ and $g(x) = \log_e x$, then the value of the integral $\int_{-\frac{\pi}{4}}^{\frac{\pi}{4}} g(f(x))\, dx$ is (1) $\log_e e$ (2) $\log_e 2$ (3) $\log_e 1$ (4) $\log_e 3$
If $f(a + b + 1 - x) = f(x)$, for all $x$, where $a$ and $b$ are fixed positive real numbers, then $\frac { 1 } { a + b } \int _ { a } ^ { b } x (f(x) + f(x + 1)) d x$ is equal to (1) $\int _ { a - 1 } ^ { b - 1 } f(x + 1) d x$ (2) $\int _ { a - 1 } ^ { b - 1 } f(x) d x$ (3) $\int _ { a + 1 } ^ { b + 1 } f(x) d x$ (4) $\int _ { a + 1 } ^ { b + 1 } f(x + 1) d x$
Which of the following statement is correct for the function $g ( \alpha )$ for $\alpha \in R$ such that $g ( \alpha ) = \int _ { \frac { \pi } { 6 } } ^ { \frac { \pi } { 3 } } \frac { \sin ^ { \alpha } x } { \cos ^ { \alpha } x + \sin ^ { \alpha } x } d x$ (1) $g ( \alpha )$ is a strictly increasing function (2) $g ( \alpha )$ has an inflection point at $\alpha = - \frac { 1 } { 2 }$ (3) $g ( \alpha )$ is a strictly decreasing function (4) $g ( \alpha )$ is an even function
Let $f : R \rightarrow R$ be a continuous function such that $f ( x ) + f ( x + 1 ) = 2$ for all $x \in R$. If $I _ { 1 } = \int _ { 0 } ^ { 8 } f ( x ) d x$ and $I _ { 2 } = \int _ { - 1 } ^ { 3 } f ( x ) d x$, then the value of $I _ { 1 } + 2 I _ { 2 }$ is equal to $\_\_\_\_$.
The value of $\int _ { 0 } ^ { \pi } \frac { e ^ { \cos x } \sin x } { ( 1 + \cos ^ { 2 } x )( e ^ { \cos x } + e ^ { - \cos x } ) } \mathrm { d } x$ is equal to