Recent questions tagged tifrmaths2011

2 2 votes
1 1 answer
1.0k
1.0k views
A gardener throws $18$ seeds onto an equilateral triangle shaped plot of land with sides of length one metre. Then at least two seeds are within a distance of $25$ centim...
2 2 votes
1 1 answer
610
610 views
Let $f$ be a continuous integrable function of $\mathbb{R}$ such that either $f(x) 0$ or $f(x) + f(x + 1) 0$ for all $x \in \mathbb{R}$. Then $\int_{-\infty}^{\infty} f...
2 2 votes
1 1 answer
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Any non-singular $k \times k$-matrix with real entries can be made singular by changing exactly one entry.
1 1 vote
0 0 answers
671
671 views
Let $S$ be a finite subset of $\mathbb{R}^{3}$ such that any three elements in $S$ span a two dimensional subspace. Then $S$ spans a two dimensional space.
1 1 vote
1 answers 1 answer
750
750 views
There exists a set $A \subset \left\{1, 2,....,100\right\}$ with $65$ elements, such that $65$ cannot be expressed as a sum of two elements in $A$.
2 2 votes
3 3 answers
2.1k
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Suppose a box contains three cards, one with both sides white, one with both sides black, and one with one side white and the other side black. If you pick a card at rand...
1 1 vote
1 1 answer
835
835 views
Let $P$ be a degree $3$ polynomial with complex coefficients such that the constant term is $2010$. Then $P$ has a root $\alpha$ with $|\alpha| 10$.
3 3 votes
2 2 answers
955
955 views
If $A$ and $B$ are $3 \times 3$ matrices and $A$ is invertible, then there exists an integer $n$ such that $A + nB$ is invertible.
2 2 votes
0 0 answers
708
708 views
There is a non-trivial group homomorphism from $S_{3}$ to $\mathbb{Z}/3\mathbb{Z}$.
1 1 vote
0 0 answers
467
467 views
Suppose $f_{n}(x)$ is a sequence of continuous functions on the closed interval $[0, 1]$ converging to $0$ point wise. Then the integral $\int_{0}^{1} f_{n}(x) \text{d}x...
2 2 votes
1 answers 1 answer
610
610 views
The symmetric group $S_{5}$ consisting of permutations on $5$ symbols has an element of order $6$.
1 1 vote
0 0 answers
568
568 views
A bounded continuous function on $\mathbb{R}$ is uniformly continuous.
1 1 vote
0 0 answers
546
546 views
There are n homomorphisms from the group $\mathbb{Z}/n\mathbb{Z}$ to the additive group of rationals $\mathbb{Q}$.
1 1 vote
1 1 answer
609
609 views
In the ring $\mathbb{Z}/8\mathbb{Z}$, the equation $x^{2}=1$ has exactly $2$ solutions.
2 2 votes
1 1 answer
755
755 views
State True or FalseLet $A$ be a $2 \times 2$-matrix with complex entries. The number of $2 \times 2$-matrices $A$ with complex entries satisfying the equation $A^{3}$ is ...
3 3 votes
2 2 answers
869
869 views
The function$f(x)= \begin{cases}0 & \text{if x is rational} \\ x& \text{if x is irrational} \end{cases}$is not continuous anywhere on the real line.
1 1 vote
0 0 answers
543
543 views
The series$\sum_{n=1}^{\infty}\frac{\sqrt{n+1}-\sqrt{n}}{n}$diverges.
1 1 vote
0 0 answers
510
510 views
The space of solutions of infinitely differentiable functions satisfying the equation$y" + y = 0$is infinite dimensional.
2 2 votes
1 1 answer
1.1k
1.1k views
There exists a group with a proper subgroup isomorphic to itself.
1 1 vote
1 1 answer
814
814 views
Any continuous function from the open unit interval $(0, 1)$ to itself has a fixed point.
1 1 vote
1 answers 1 answer
796
796 views
The equation $63x + 70y + 15z = 2010$ has an integral solution.
1 1 vote
1 1 answer
807
807 views
The derivative of the function$\int_{0}^{\sqrt{x}} e^{-t^{2}}dt$at $x = 1$ is $e^{-1}$ .
2 2 votes
0 0 answers
600
600 views
Consider the map $T$ from the vector space of polynomials of degree at most $5$ over the reals to $R \times R$, given by sending a polynomial $P$ to the pair $(P(3), P' (...
1 1 vote
1 answers 1 answer
738
738 views
The value of the infinite product$\prod_{n=2}^{\infty} (1-\frac{1}{n^{2}})$is 1.
1 1 vote
2 2 answers
1.1k
1.1k views
The polynomial $x^{4}+7x^{3}-13x^{2}+11x$ has exactly one real root.
1 1 vote
1 1 answer
802
802 views
If $A, B$ are closed subsets of $[0,\infty)$, then$A + B = \left\{x + y | x \in A, y \in B\right\}$is closed in $[0,\infty)$
1 1 vote
1 1 answer
2.0k
2.0k views
$\log x$ is uniformly continuous on $( \frac{1}{2}, \infty)$.
4 4 votes
2 2 answers
1.1k
1.1k views
$A$ is $3 \times 4$-matrix of rank $3$. Then the system of equations,$Ax = b$has exactly one solution.
1 1 vote
1 1 answer
853
853 views
2 2 votes
1 1 answer
609
609 views
For any real number $c$, the polynomial $x^{3}+x+c$ has exactly one real root.