∫（5π/4，π/4）(1+sin²x)dx=∫（5π/4，π/4）[1+½(1-cos2x)]dx=∫（5π/4，π/4）(3/2)-½cos2x)dx=(3/2)x|（5π/4，π/4） -¼sin2x|（5π/4，π/4）=3/2（5π/4-π/4）-1/4(sin5π/2-sinπ/2）=3π/2
你这个最好悬赏。
