MCQ
If $\cot(\alpha+\beta)=0,$ then $\sin(\alpha+2\beta)$ is equal to:
  • $\sin\alpha$
  • B
    $\cos2\beta$
  • C
    $\cos\alpha$
  • D
    $\sin2\alpha$

Answer

Correct option: A.
$\sin\alpha$
Given:
$\cot(\alpha+\beta)=0$
$\Rightarrow\frac{\cos(\alpha+\beta)}{\sin(\alpha+\beta)}=0$
$\Rightarrow\cos(\alpha+\beta)=0$
$\Rightarrow\alpha+\beta=\frac\pi2$
$\therefore\sin(\alpha+2\beta)=\sin(\alpha+\alpha+\beta)$
$=\sin\alpha$

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

If the value of $\left(1+\frac{2}{3}+\frac{6}{3^{2}}+\frac{10}{3^{3}}+\ldots \text { upto } \infty\right)^{\log _{(0.25)}\left(\frac{1}{3}+\frac{1}{3^{2}}+\frac{1}{3^{3}}+\ldots . \text { uptow }\right)}$ is $l$, then $l^{2}$ is equal to $......$
Let $\alpha, \beta \in \mathrm{N}$ be roots of equation $\mathrm{x}^2-70 \mathrm{x}+\lambda=0$, where $\frac{\lambda}{2}, \frac{\lambda}{3} \notin \mathrm{N}$. If $\lambda$ assumes the minimum possible value, then $\frac{(\sqrt{\alpha-1}+\sqrt{\beta-1})(\lambda+35)}{|\alpha-\beta|}$ is equal to :
A point $P$ moves inside a square of area $4$ square units such that it is nearer to point of intersection of its diagonal than any vertex. Area of the region traced by $P$ is
Choose the correct answer. If the middle term of $\Big(\frac{1}{\text{x}}+\text{x}\sin\text{x}\Big)^{10}$ is equal to $7\frac{7}{8},$ then value of x is:
Hint: $\text{T}_6=\ ^{10}\text{C}_5\frac{1}{\text{x}^5}.\text{x}^5\ \sin^5\text{x}=\frac{63}{8}\Rightarrow\sin^5\text{x}=\frac{1}{2^5}\sin\frac{1}{2}$ $\Rightarrow\text{x}=\text{n}\pi+(-1)^\text{n}\frac{\pi}{6}$
$\mathop {\lim }\limits_{x \to \infty } \sqrt x (\sqrt {x + 5} - \sqrt x ) = $
The relation R defined on the set $A=\{1,2,3,4,5\}$ by $R=\left\{(x, y):\left|x^2-y^2\right|<16\right\}$ is given by:
Two candidates attempt to solve the equation ${x^2} + px + q = 0$. One starts with a wrong value of p and finds the roots to be $2$ and $6$ and the other starts with a wrong value of $q$ and find the roots to be $2$ and $-9$. The roots of the original equation are
The number of ways to give away $25$ apples to $4$ boys, each boy receiving at least $4$ apples, are
The value of $\sin^25^\circ+\sin^210^\circ+\sin^215^\circ+\ ...\ +\sin^285^\circ+\sin^290^\circ$ is:
Let $A_{1}, A_{2}, A_{3}, \ldots \ldots . .$ be squares such that for each $n \geq 1,$ the length of the side of $A _{ n }$ equals the length of diagonal of $A _{ n +1}$. If the length of $A _{1}$ is $12\, cm ,$ then the smallest value of $n$ for which area of $A _{ n }$ is less than one, is ..........