用罗必达法则:1. lim (x→3pi/2) [cos7x/(x-3pi/2)]= lim (x→3pi/2)(-sin7x * 7)/1 = -7sin(21pi/2) = -72. lim→0 [sin^2 (5teta) / (5teta) ]= lim→0 (2sin(5theta) * cos(5theta)* 5/5 = 0
前一个等于 -7后一个等于 0洛比达公式呗