送交者: wasguru 于 2009-10-29, 00:32:37:

回答: sum_j (v_j-V)^2 = sum_j ( (v_j+V') - (V+V') )^2 is an identity! 由 gyro 于 2009-10-29, 00:21:19:

• Nothing is assumed about dV/dt for the identity to be valid. (无内容) - gyro (0 bytes) 2009-10-29, 00:42:47 (378191)

加跟贴