If $y = x - {x^2} + {x^3} - {x^4} + ......\infty $, then value of $x$ will be
$y + \frac{1}{y}$
$\frac{y}{{1 + y}}$
$y - \frac{1}{y}$
$\frac{y}{{1 - y}}$
Let $S_1$ be the sum of areas of the squares whose sides are parallel to coordinate axes. Let $S_2$ be the sum of areas of the slanted squares as shown in the figure. Then, $\frac{S_1}{S_2}$ is equal to
The first term of a $G.P.$ whose second term is $2$ and sum to infinity is $8$, will be
Evaluate $\sum\limits_{k = 1}^{11} {\left( {2 + {3^k}} \right)} $
If ${\log _a}x,\;{\log _b}x,\;{\log _c}x$ be in $H.P.$, then $a,\;b,\;c$ are in
The sum of two numbers is $6$ times their geometric mean, show that numbers are in the ratio $(3+2 \sqrt{2}):(3-2 \sqrt{2})$