求大神解答高数题,r=8asin3⊙的面积

2024-11-02 20:17:14
推荐回答(1个)
回答1:

r=8asinθ>0
θ∈[0,π]
面积=1/2∫(0,π)(8asinθ)²dθ
=16a²∫(0,π)1-cos2θdθ
=16a²π