e的x次方cosxdx求不定积分
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e的x次方cosxdx求不定积分
![e的x次方cosxdx求不定积分](/uploads/image/z/18210491-35-1.jpg?t=e%E7%9A%84x%E6%AC%A1%E6%96%B9cosxdx%E6%B1%82%E4%B8%8D%E5%AE%9A%E7%A7%AF%E5%88%86)
∫e^xcosxdx=∫cosxd(e^x)
= cosx.e^x + ∫sinx .(e^x) dx
= cosx.e^x + ∫sinx .d(e^x)
= cosx .e^x + sinx.e^x - ∫ cosx(e^x) dx
2∫e^xcosxdx =cosx .e^x + sinx.e^x
∫e^xcosxdx =(1/2)[cosx .e^x + sinx.e^x] + C
再问: 谢谢!那么极限lim(x—>0) (∫上限x 下限0 e的t次方costdt)除以(sinx)怎么算啊?
再答: lim(x->0) ∫(0->x) e^tcostdt / (sinx) (0/0) =lim(x->0) e^xcosx / cosx =lim(x->0) e^x =1
= cosx.e^x + ∫sinx .(e^x) dx
= cosx.e^x + ∫sinx .d(e^x)
= cosx .e^x + sinx.e^x - ∫ cosx(e^x) dx
2∫e^xcosxdx =cosx .e^x + sinx.e^x
∫e^xcosxdx =(1/2)[cosx .e^x + sinx.e^x] + C
再问: 谢谢!那么极限lim(x—>0) (∫上限x 下限0 e的t次方costdt)除以(sinx)怎么算啊?
再答: lim(x->0) ∫(0->x) e^tcostdt / (sinx) (0/0) =lim(x->0) e^xcosx / cosx =lim(x->0) e^x =1