Prove that three points are collinear using their corresponding vectors.
83449
Proof with 3D vectors
59644
Proof of Cartesian product intersection
150528
Pythagorean triples $(a,b,c)$ and divisibility of $a$ or $b$ by $3$.
93875
"Show" that the direction cosines of a vector satisfies...
62065
Prove that $v_1, \dots v_n$ is a basis of V.
145756
Collinearity problem (Newton-Gauss line)
6547
Given $3$-dimensional subspaces $V, W \subset \Bbb R^5$, there is a nonzero vector in $V \cap W$
88605
Proof of the Reverse Triangle Inequality
94077
Proof of linear independence of $e^{at}$
34272
Proving definition of norms induced by vector norms
116823
VERIFYING: Proving an $n \times n$ Matrix Vector Space
109767
Prove that three points are enough to draw/define one and only one circle
37794
Proving the two given vectors are orthogonal
130109
Equilateral Triangle from three complex points
94580
Prove that, $\binom{3n}{r}=\binom{3n-1}{r} + \binom{3n-1}{r-1}$
27954
Prove triangle inequality using the properties of absolute value
127380
Use vectors to prove $\cos(\beta - \alpha) = \cos \alpha \cos\beta + \sin\alpha \sin\beta$