Question

设集合A={x|x^2+3k^2≥2k(2x-1)},B={x|x^2-(2x-1)k+k^2≥0},且A包含于B,试求

Answer 1

x^2+3k^2>=4kx-2k

x^2-4kx+3k^2+2k>=0

即最低点要大于等于0

所以当x=2k时x^2-4kx+3k^2+2k>=0

4k^2-8k^2+3k^2+2k>=0

-k^2+2k>=0

0