求助一下这道不定积分题怎么做
∫[x²/√(a²-x²)]dx
=-0.5∫[x/√(a²-x²)]d(a²-x²)
=-∫xd√(a²-x²)
=-x√(a²-x²)+∫√(a²-x²)dx
=-x√(a²-x²)+∫[(a²-x²)/√(a²-x²)]dx
=-x√(a²-x²)+a²∫dx/√(a²-x²)-∫[x²/√(a²-x²)]dx
=0.5[-x√(a²-x²)+a²∫d(x/a)/√(1-x²/a²)]
=-0.5x√(a²-x²)+0.5a²arcsin(x/a)+c
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