Dot product formula proof
115295
Why are the two dot product definitions equal?
24585
Proving that $\mathbf{W}$+$\mathbf{W^{\perp}}$=$\mathbb{R^{n}}$
16548
Prove $(x+y) \text{ mod } n = ((x \text{ mod } n)+(y \text{ mod } n)) \text{ mod } n,\,$ and product analog
33903
Prove that $(1+a_1) \cdot (1+a_2) \cdot \dots \cdot (1+a_n) \geq 2^n$
111515
Proving that $-a=(-1)\cdot a$
107290
proof of product rule of derivatives using first principle?
53426
Proof of a formula involving Euler's totient function: $\varphi (mn) = \varphi (m) \varphi (n) \cdot \frac{d}{\varphi (d)}$
118996
Prove that $T$ is an orthogonal projection
123967
Proof of a generating functions formula
21363
Prove the uniqueness of an inner product
60777
Prove $\, a_1 \Bbb Z \cap \dotsb \cap a_r \mathbb{Z} = {\rm lcm}(a_1, \ldots, a_r) \Bbb Z$
77253
Proof of Lagrange Identity
81181
Prove that $\det(M-I)=0$ if $\det(M)=1$ and $MM^T=I$
54737
Proof that $V = \sum_k U_k$ and $\dim V=\sum_k \dim U_k$ implies $V=\oplus_k U_k$
72551
Proof that $\rho = \pm1$ implies linear combination
46106
Prove that $D_r \circ D_s = \{ (x,y) \in \mathbb{R}^2 \ | \ |x-y|<r+s \}$, where $D_a = \{ (x,y) \in \mathbb{R}^2\ | \ |x-y| < a \}$
52750
Prove that $f^\ast\omega=\det f \cdot \omega$