https://www.khanacademy.org/math/linear-algebra/vectors-and-spaces/dot-cross-products/v/vector-dot-product-and-vector-length
忘光光了
posted on 2018-11-05 15:56 明天有风吹 阅读(242) 评论(0) 编辑 收藏 举报
+V atob('d2h5X251bGw=')
请备注：from博客园
