设向量a的绝对值=1,向量b的绝对值=2向量a乘以向量b=-根号三,求向量a乘以向量b

2025-06-21 22:18:10
推荐回答(2个)
回答1:

若是 |a| = 1, |b| = 2, 向量 a · b = -√3,
a · b = |a| |b| cosθ = 2cosθ = -√3, cosθ = - √3/2
则 |a×b| = |a| |b| sinθ = 2 · 1/2 = 1

回答2:

若是 |a| = 1, |b| = 2, 向量 a · b = -√3,
a · b = |a| |b| cosθ = 2cosθ = -√3, cosθ = - √3/2
则 |a×b| = |a| |b| sinθ = 2 · 1/2 = 1