3b2≥λb(a b)include

3b2≥λb(a b)include
3b2≥λb(a b)include

3b2≥λb(a b)include
19.6 x 14.2 x 5.2 cm假设1n（M N）=1nM 1nM假设y=k/x（k≠0）y=cosx=sin（x 丌/2)