MCQ
If $1 + \sin x + {\sin ^2}x + .....$ to $\infty = 4 + 2\sqrt 3 ,\,0 < x < \pi ,$ then
  • A
    $x = \frac{\pi }{6}$
  • B
    $x = \frac{\pi }{3}$
  • C
    $x = \frac{\pi }{3}$ or $\frac{\pi }{6}$
  • $x = \frac{\pi }{3}$ or $\frac{{2\pi }}{3}$

Answer

Correct option: D.
$x = \frac{\pi }{3}$ or $\frac{{2\pi }}{3}$
d
(d) $1 + \sin x + {\sin ^2}x + ....\infty = 4 + 2\sqrt 3 $

$ \Rightarrow $ $\frac{1}{{1 - \sin x}} = 4 + 2\sqrt 3 $

$ \Rightarrow $ $\sin x = 1 - \frac{1}{{4 + 2\sqrt 3 }}$

$ \Rightarrow $ $\sin x = 1 - \frac{{(4 - 2\sqrt 3 )}}{4} = \frac{{2\sqrt 3 }}{4} = \frac{{\sqrt 3 }}{2}$

$ \Rightarrow $ $x = \frac{\pi }{3}$ or $\frac{{2\pi }}{3}$.

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

The equation of pair of tangents to the circle ${x^2} + {y^2} - 2x + 4y + 3 = 0$ from $(6, - 5)$, is
If the vertex of the parabola $y = {x^2} - 8x + c$ lies on $x$ - axis, then the value of $c$ is
A pack contains $n$ card numbered from $1$ to $n$. Two consecutive numbered card are removed from the pack and the sum of the numbers on the remaining cards is $1224$. If the smaller of the numbers on the removed cards is $k$, then $k -20=$
Let $L_{1}$ be a tangent to the parabola $y ^{2}=4( x +1)$ and $L _{2}$ be a tangent to the parabola $y ^{2}=8( x +2)$ such that $L _{1}$ and $L _{2}$ intersect at right angles. Then $L_{1}$ and $L_{2}$ meet on the straight line
There are $19 $hockey players in a club. On a particular day $14$ were wearing the prescribed hockey shirts, while $11$ were wearing the prescribed hockey pants. None of then was without hockey pant or hockey shirt. How many of them were in complete hockey uniform?
If the coefficients of $x^4, x^5$ and $x^6$ in the expansion of $(1+x)^n$ are in the arithmetic progression, then the maximum value of $n$ is :
If the in centre of an equilateral triangle is $(1, 1)$ and the equation of its one side is $3x + 4y + 3\,= 0$, then the equation of the circumcircle of this triangle is
If the area of the triangle whose one vertex is at the vertex of the parabola, ${y^2} + 4\,\left( {x - {a^2}} \right) = 0$ and the other two vertices are the points of intersection of the parabola and $y -$ axis, is $250\, sq$. units, then a value of $‘a’$ is
An equation of sphere with centre at origin and radius $r$ can be represented as:
How many numbers of $6$ digits can be formed from the digits of the number $112233$