integral from 4 to infinity of 7e^{-y/2}

解答

\int_{4}^{\infty} 7 e^{- \frac{y}{2}} d y

\frac{14}{e ^{2}}

十进制

1.89469 \dots

求解步骤

\int_{4}^{\infty} 7 e^{- \frac{y}{2}} d y

计算不定积分:

\int 7 e^{- \frac{y}{2}} d y = - 14 e^{- \frac{y}{2}} + C

带入上下限计算后得:

\int_{4}^{\infty} 7 e^{- \frac{y}{2}} d y = 0 - (- \frac{14}{e ^{2}})

= 0 - (- \frac{14}{e ^{2}})

化简

= \frac{14}{e ^{2}}

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