|a|=2,|b|=1,a与b的夹角为π/3,若向量2a+kb与a+b垂直,求k的值
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/17 20:40:20
![|a|=2,|b|=1,a与b的夹角为π/3,若向量2a+kb与a+b垂直,求k的值](/uploads/image/z/5544974-38-4.jpg?t=%7Ca%7C%3D2%2C%7Cb%7C%3D1%2Ca%E4%B8%8Eb%E7%9A%84%E5%A4%B9%E8%A7%92%E4%B8%BA%CF%80%2F3%2C%E8%8B%A5%E5%90%91%E9%87%8F2a%2Bkb%E4%B8%8Ea%2Bb%E5%9E%82%E7%9B%B4%2C%E6%B1%82k%E7%9A%84%E5%80%BC)
x)I5ҩI5I|/KvX>Ɏ]u^t/}:a~D$DޢlcS6H}"}_`gCgU%&U%q 똩 Jiō㌴54qFPqmv6mkj_\g2 X/
|a|=2,|b|=1,a与b的夹角为π/3,若向量2a+kb与a+b垂直,求k的值
|a|=2,|b|=1,a与b的夹角为π/3,若向量2a+kb与a+b垂直,求k的值
|a|=2,|b|=1,a与b的夹角为π/3,若向量2a+kb与a+b垂直,求k的值
|a|=2,|b|=1,a与b的夹角为π/3
ab=|a||b|cos60=1
向量2a+kb与a+b垂直
则 (2a+kb)*(a+b)=0
2a^2+(k+2)ab+kb^2=0
8+k+2+k=0
k=-5