Question
Evaluate the following integrals:$\int_{0}^\limits{\text{a}}\frac{\text{x}}{\sqrt{\text{a}^2+\text{x}^2}}\text{ dx}$

Answer

Let $\text{a}^2+\text{x}^2=\text{t}^2$ Differentiating w.r.t. x, we get$2\text{xdx}=2\text{tdt}$
$\text{xdx}=\text{tdt}$
Now, $\text{x}=0\Rightarrow\text{t}=0$$\text{x}=\text{a}\Rightarrow\text{t}=\sqrt{2}\text{a}$
$\therefore\ \int_{0}^\limits{\text{a}}\frac{\text{x}}{\sqrt{\text{a}^2+\text{x}^2}}\text{ dx}=\int_{\text{a}}^\limits{\sqrt{2\text{a}}}\frac{\text{t dt}}{\text{t}}$
$=\int_{\text{a}}^\limits{\sqrt{2\text{a}}}\text{dt}$
$=\big[\text{t}\big]^{\sqrt{2}\text{a}}_\text{a}$
$=\big[\sqrt{2}\text{a}-\text{a}\big]$
$=\text{a}\big(\sqrt{2}-1\big)$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Find the maximum and the minimum values, if any, without using derivaives of the following functions:$f(x) = 2x^3+ 5$ on $R$.
Evaluate :

$\int_{-\pi / 4}^{\pi / 4} \frac{x+\frac{\pi}{4}}{2-\cos 2 x} \cdot d x$

Two dice are thrown together and the total score is noted. The event E, F and G are "a total of 4", "a total of 9 or more", and "a total divisible by 5", respectively. Calculate P(E), P(F) and P(G) and decide which pairs of events, if any, are independent.
Evaluate the following integrals:
$\int\frac{1}{(2\text{x}^2+3)\sqrt{\text{x}^2-4}}\text{ dx}$
If $\text{y}=\cos^{-1}(2\text{x})+2\cos^{-1}\sqrt{1-4\text{x}^2}, -\frac{1}{2}<\text{x}<0,$ find $\frac{\text{dy}}{\text{dx}}.$
Define a binary operation * on the set {0, 1, 2, 3, 4, 5} as:
$\text{a}\times\text{b}=\begin{cases}\text{a + b},&\text{if }\text{a + b}<6\\\text{a + b}-6,&\text{if }\text{a + b}\geq6\end{cases}$
Show that 0 is the identity for this operation and each element a ≠ 0 of the set is invertible with 6 − a being the inverse of a.
Find $A^{-1},$ If $\text{A}=\begin{bmatrix}1&2&5\\ 1&-1&-1\\ 2&3&-1\end{bmatrix}$. Hence solve the follwing system of linear equations:
$x + 2y +5z = 10, x- y - z = - 2, 2x + 3y - z = - 11$
Find the second order derivatives of the following functions:
$\text{e}^{6\text{x}} \cos \text{x}$
A small firm manufacturers items A and B. The total number of items A and B that it can manufacture in a day is at the most $24$. Item A takes one hour to make while item B takes only half an hour. The maximum time available per day is $16$ hours. If the profit on one unit of item A be $Rs. 300$ and one unit of item B be $Rs. 160$, how many of each type of item be produced to maximize the profit? Solve the problem graphically.
Let $L$ be the set of all lines in $X Y$-plane and $R$ be the relation in $L$ defined as $R=\left\{\left(L_1, L_2\right): L_1\right.$ is parallel to $\left.L_2\right\}$. Show that $R$ is an equivalence relation. Find the set of all lines related to the line $y=2 x+4$.