算芦历那个陪告搜积分原式=√2a³×∫(-π,π)(1-cost)^(5/2)dt=2√2a³∫(0,π)(1-cost)^(5/2)dt=2√2a³∫(0,π)(2sin²t/2)^(5/友基2)dt令t/2=u原式=4√2a³∫(0,π/2)(2sin²u)^(5/2)du=32a³∫(0,π/2)(sinu)^5du=32a³×4/5×2/3×1=256a³/15.
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