Recent questions tagged isi2014-dcg

2 2 votes
2 2 answers
1.1k
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Let $(1+x)^n = C_0+C_1x+C_2x^2+ \dots + C_nx^n$, $n$ being a positive integer. The value of$$\left( 1+\dfrac{C_0}{C_1} \right) \left( 1+\dfrac{C_1}{C_2} \right) \cdots \l...
4 4 votes
1 1 answer
1.8k
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Let $a_n=\bigg( 1 – \frac{1}{\sqrt{2}} \bigg) \cdots \bigg( 1 – \frac{1}{\sqrt{n+1}} \bigg), \: n \geq 1$. Then $\underset{n \to \infty}{\lim} a_n$equals $1$does not exi...
5 5 votes
4 4 answers
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$\underset{x \to \infty}{\lim} \left( \frac{3x-1}{3x+1} \right) ^{4x}$ equals$1$$0$$e^{-8/3}$$e^{4/9}$
3 3 votes
4 4 answers
3.3k
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$\underset{n \to \infty}{\lim} \dfrac{1}{n} \bigg( \dfrac{n}{n+1} + \dfrac{n}{n+2} + \cdots + \dfrac{n}{2n} \bigg)$ is equal to$\infty$$0$$\log_e 2$$1$
2 2 votes
1 1 answer
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Consider the sets defined by the real solutions of the inequalities$A = \{(x,y):x^2+y^4 \leq 1\} \:\:\:\:\:\:\: B=\{(x,y):x^4+y^6 \leq 1\}$ Then$B \subseteq A$$A \subsete...
2 2 votes
2 2 answers
921
921 views
If $f(x)$ is a real valued function such that $2f(x)+3f(-x)=15-4x$, for every $x \in \mathbb{R}$, then $f(2)$ is$-15$$22$$11$$0$
2 2 votes
3 3 answers
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If $f(x) = \dfrac{\sqrt{3} \sin x}{2+\cos x}$, then the range of $f(x)$ isthe interval $[-1 , \sqrt{3}{/2}]$the interval $[-\sqrt{3}{/2}, 1]$the interval $[-1, 1]$none of...
3 3 votes
3 3 answers
1.5k
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If $M$ is a $3 \times 3$ matrix such that $\begin{bmatrix} 0 & 1 & 2 \end{bmatrix}M=\begin{bmatrix}1 & 0 & 0 \end{bmatrix}$ and $\begin{bmatrix}3 & 4 & 5 \end{bmatrix} M ...
3 3 votes
1 1 answer
812
812 views
The values of $\eta$ for which the following system of equations$$\begin{array} {} x & + & y & + & z & = & 1 \\ x & + & 2y & + & 4z & = & \eta \\ x & + & 4y & + & 10z & ...
6 6 votes
3 3 answers
1.8k
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The number of divisors of $6000$, where $1$ and $6000$ are also considered as divisors of $6000$ is$40$$50$$60$$30$
1 1 vote
1 1 answer
720
720 views
Let $x_1$ and $x_2$ be the roots of the quadratic equation $x^2-3x+a=0$, and $x_3$ and $x_4$ be the roots of the quadratic equation $x^2-12x+b=0$. If $x_1, x_2, x_3$ and ...
2 2 votes
1 answers 1 answer
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The integral $$\int _0^{\frac{\pi}{2}} \frac{\sin^{50} x}{\sin^{50}x +\cos^{50}x} dx$$ equals$\frac{3 \pi}{4}$$\frac{\pi}{3}$$\frac{\pi}{4}$none of these
2 2 votes
1 1 answer
854
854 views
Let the function $f(x)$ be defined as $f(x)=\mid x-1 \mid + \mid x-2 \:\mid$. Then which of the following statements is true?$f(x)$ is differentiable at $x=1$$f(x)$ is di...
1 1 vote
1 1 answer
641
641 views
$x^4-3x^2+2x^2y^2-3y^2+y^4+2=0$ representsA pair of circles having the same radiusA circle and an ellipseA pair of circles having different radiinone of the above
3 3 votes
1 1 answer
1.0k
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Let $\mathbb{N}=\{1,2,3, \dots\}$ be the set of natural numbers. For each $n \in \mathbb{N}$, define $A_n=\{(n+1)k, \: k \in \mathbb{N} \}$. Then $A_1 \cap A_2$ equals$A_...
2 2 votes
2 2 answers
1.0k
1.0k views
The sum of the series $\dfrac{1}{1.2} + \dfrac{1}{2.3}+ \cdots + \dfrac{1}{n(n+1)} + \cdots $ is$1$$1/2$$0$non-existent
2 2 votes
3 3 answers
1.2k
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$\underset{x \to 2}{\lim} \dfrac{1}{1+e^{\frac{1}{x-2}}}$ is$0$$1/2$$1$non-existent
2 2 votes
3 3 answers
1.5k
1.5k views
$^nC_0+2^nC_1+3^nC_2+\cdots+(n+1)^nC_n$ equals$2^n+n2^{n-1}$$2^n-n2^{n-1}$$2^n$none of these
3 3 votes
1 1 answer
868
868 views
It is given that $e^a+e^b=10$ where $a$ and $b$ are real. Then the maximum value of $(e^a+e^b+e^{a+b}+1)$ is$36$$\infty$$25$$21$
0 0 votes
1 1 answer
676
676 views
If $A(t)$ is the area of the region bounded by the curve $y=e^{-\mid x \mid}$ and the portion of the $x$-axis between $-t$ and $t$, then $\underset{t \to \infty}{\lim} A(...
2 2 votes
1 1 answer
793
793 views
Suppose that the function $h(x)$ is defined as $h(x)=g(f(x))$ where $g(x)$ is monotone increasing, $f(x)$ is concave, and $g’’(x)$ and $f’’(x)$ exist for all $x$. Then $h...
2 2 votes
2 2 answers
858
858 views
The conditions on $a$, $b$ and $c$ under which the roots of the quadratic equation $ax^2+bx+c=0 \: ,a \neq 0, \: b \neq 0 $ and $c \neq 0$, are unequal magnitude but of t...
5 5 votes
2 answers 2 answers
917
917 views
The sum of the series $\:3+11+\dots +(8n-5)\:$ is$4n^2-n$$8n^2+3n$$4n^2+4n-5$$4n^2+2$
0 0 votes
1 1 answer
659
659 views
Let $f(x) = \dfrac{2x}{x-1}, \: x \neq 1$. State which of the following statements is true.For all real $y$, there exists $x$ such that $f(x)=y$For all real $y \neq 1$, ...
2 2 votes
1 1 answer
746
746 views
The determinant $\begin{vmatrix} b+c & c+a & a+b \\ q+r & r+p & p+q \\ y+z & z+x & x+y \end{vmatrix}$ equals$\begin{vmatrix} a & b & c \\ p & q & r \\ x & y & z \end{vm...
2 2 votes
1 1 answer
684
684 views
Let $x_1 x_2>0$. Then which of the following is true?$\log \big(\frac{x_1+x_2}{2}\big) \frac{\log x_1+ \log x_2}{2}$$\log \big(\frac{x_1+x_2}{2}\big) < \frac{\log x_1+ ...
0 0 votes
0 0 answers
651
651 views
Let $y^2-4ax+4a=0$ and $x^2+y^2-2(1+a)x+1+2a-3a^2=0$ be two curves. State which one of the following statements is true.These two curves intersect at two pointsThese two ...
2 2 votes
2 2 answers
870
870 views
The area enclosed by the curve $\mid\: x \mid + \mid y \mid =1$ is$1$$2$$\sqrt{2}$$4$
0 0 votes
2 2 answers
1.3k
1.3k views
If $f(x) = \sin \bigg( \dfrac{1}{x^2+1} \bigg),$ then$f(x)$ is continuous at $x=0$, but not differentiable at $x=0$$f(x)$ is differentiable at $x=0$, and $f’(0) \neq 0$$f...
2 2 votes
1 1 answer
702
702 views
Consider the equation $P(x) =x^3+px^2+qx+r=0$ where $p,q$ and $r$ are all real and positive. State which of the following statements is always correct.All roots of $P(x) ...