65 Mathematical symbol for 'slightly greater than'? 35 Suppose $M$ is an $m \times n$ matrix such that all rows and columns of $M$ sum to $1$. Show that $m=n$ 12 How many digits does the integer zero have? 11 Proving $x^2+x+1\gt0$ 8 probability that a sum of 3 is rolled before a sum of 5 is rolled in a sequence of rolls of the dice from a four sided die.

### Reputation (12,902)

 +15 Rewriting inequality given by a fraction +10 $7^n + 2\cdot 4^n$ is divisible by $3$ (Proof by induction) +10 Does Fractional Calculus define the derivative over the Weirstrass Function? +15 Coin flipping, chances for second coin being heads

### Questions (68)

 8 Diagonal-free Sudoku grid 8 '3-point' curve 6 Probability question using fixed steps 5 Number of digits $d$ in $d^k$ 5 Improvement on $\phi(n)\sigma(n)/n^2$ bounds?

### Tags (277)

 105 algebra-precalculus × 53 67 linear-algebra × 30 97 calculus × 32 51 probability × 74 89 real-analysis × 31 48 elementary-number-theory × 50 89 notation × 14 46 discrete-mathematics × 43 82 combinatorics × 75 42 matrices × 12