a生活的最高境界是宽容,相处的最高境界是尊重 The life highest boundary is tolerant, is together the highest boundary is the respect [translate] a容易证明,绝对值函数满足三角不等式 Easy to prove that, the absolute value function satisfies the triangle inequality [translate] ...
By setting the vectors to be the two sides of a triangle with sides a and b and the angle between them as theta, we can use the inequality to prove that the length of the third side (c) must be a real number, thus proving the existence of real values for a, ...