MCQ
$\int_a^b \frac{\sqrt{x}}{\sqrt{x}+\sqrt{a+b-x}} d x=$
  • A
    $a+b$
  • B
    $\frac{b-a}{2}$
  • C
    $a-b$
  • D
    $\frac{a-b}{2}$

Answer

$
\begin{aligned}
& \text {(b) : Let } I=\int_a^b \frac{\sqrt{x}}{\sqrt{x}+\sqrt{a+b-x}} d x ...(i) \\
& \Rightarrow I=\int_a^b \frac{\sqrt{a+b-x}}{\sqrt{a+b-x}+\sqrt{x}} d x ..(ii) \\
& {\left[\because \int_a^b f(x) d x=\int_a^b f(a+b-x) d x\right]}
\end{aligned}
$
Adding (i) and (ii), we get
$
\begin{aligned}
& 2 I=\int_a^b \frac{\sqrt{x}+\sqrt{a+b-x}}{\sqrt{x}+\sqrt{a+b-x}} d x=\int_a^b d x=[x]_a^b=b-a \\
& \Rightarrow I=\frac{b-a}{2}
\end{aligned}
$

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