Tim

### Questions (15)

 5 Is there a method that can allow us to know how to prove theorems (number theory)? 3 How do you prove that $\binom{n}{d} = \Theta(n^d)$? 1 Stuck on the Proof on Fisher's Inequality 1 A connected simple graph $G$ with $n$ vertices is a tree if and only if $P_G(x) = x(x − 1)^{n−1}$ . 1 How to prove the Cofactor Expansion Theorem for Determinant of a Matrix?

### Reputation (92)

 -2 Why is the Fano plane a Projective Plane? +8 A connected simple graph $G$ with $n$ vertices is a tree if and only if $P_G(x) = x(x − 1)^{n−1}$ . +5 Stuck on the Proof on Fisher's Inequality +5 How to prove the Cofactor Expansion Theorem for Determinant of a Matrix?

 2 $A^2 + A + I_n = 0 \implies$ matrix $A$ is invertible 0 If $m*n$ divides k, then both m divides k and n divides k 0 For which values of L does the vector [l,3,-5] belong to span {[1,0,-2],[-3,1,7]?

### Tags (26)

 2 linear-algebra × 6 0 polynomials × 3 2 matrices × 3 0 greatest-common-divisor × 2 0 combinatorics × 6 0 number-theory × 2 0 elementary-number-theory × 4 0 determinant × 2 0 graph-theory × 4 0 proof-writing × 2

### Account (1)

 Mathematics 92 rep 7