MCQ
If $\int_{}^{} {(\sin 2x - \cos 2x)} \;dx = \frac{1}{{\sqrt 2 }}\sin (2x - a) + b$, then
  • A
    $a = \frac{\pi }{4},\;b = 0$
  • B
    $a = - \frac{\pi }{4},\;b = 0$
  • C
    $a = \frac{{5\pi }}{4},\;b = $any constant
  • $a = - \frac{{5\pi }}{4},\;b = $any constant

Answer

Correct option: D.
$a = - \frac{{5\pi }}{4},\;b = $any constant
d
(d)$\int_{}^{} {(\sin 2x - \cos 2x)\,dx = \frac{1}{{\sqrt 2 }}\sin (2x - a) + b} $
$ \Rightarrow - \frac{1}{2}(\sin 2x + \cos 2x) = \frac{1}{{\sqrt 2 }}\sin (2x - a) + b$
$ \Rightarrow - \left[ {\frac{1}{{\sqrt 2 }}\sin 2x + \frac{1}{{\sqrt 2 }}\cos 2x} \right] = \sin (2x - a) + b\sqrt 2 $
$ \Rightarrow \sin \left( {2x + \frac{{5\pi }}{4}} \right) = \sin (2x - a) + b\sqrt 2 $
$ \Rightarrow b$ is any constant and $a = \frac{{ - 5\pi }}{4}$.

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

A box contains $10$ good articles and $6$ with defects. One item is drawn at random. The probability that it is either good or has a defect is,
If there is an error of $a\%$ in measuring the edge of a cube, then percentage error in its surface is :
If one of the roots of $\left |\begin{matrix} 3 &\text{amp; 5} &\text{amp; x}\\ 7 &\text{amp; x} &\text{amp; 7}\\ \text{x} &\text{amp; 5} &\text{amp; 3}\end{matrix}\right |=0$ is $-10,$ the other roots are:
If $\text{f(x)}=\begin{cases}\text{mx}+1,&\text{x}\leq\frac{\pi}{2}\\\sin\text{x}+\text{n},&\text{n}>\frac{\pi}{2}\end{cases}$ is continuous at $\text{x}=\frac{\pi}{2},$ then:
The order and degree of the differential equation $\left(y^{\prime \prime \prime}\right)^2+\left(y^{\prime \prime}\right)^3-\left(y^{\prime}\right)^4+y^5=0$ is :
The solution of the equation $\frac{d y}{d x}+2 x=e^{3 x}$ is :
Let $\vec{a}=\hat{i}+\hat{j}+2 \hat{k}, \vec{b}=2 \hat{i}-3 \hat{j}+\hat{k}$ and $\overrightarrow{ c }=\hat{ i }-\hat{ j }+\hat{ k }$ be three given vectors. Let $\vec{v}$ be a vector in the plane of $\vec{a}$ and $\overrightarrow{ b }$ whose projection on $\overrightarrow{ c }$ is $\frac{2}{\sqrt{3}}$. If $\overrightarrow{ v } . \hat{ j }=7$, then $\overrightarrow{ v } \cdot(\hat{ i }+\hat{ k })$ is equal to
The function $y =\frac{{2x\,\, - \,\,1}}{{x\,\, - \,\,2}} (x \ne 2)$
If $a = i - 2j + 3k$ and $b = 3i + j + 2k,$ then the unit vector perpendicular to $a$  and  $b$  is
$\int {\frac{{dx}}{{{x^2} + 4x + 13}}} $ is equal to