integral of sec(3t)tan(3t)

解答

\int sec (3 t) tan (3 t) d t

\frac{1}{3} sec (3 t) + C

求解步骤

\int sec (3 t) tan (3 t) d t

使用换元积分法

= \int \frac{1}{3} d u

常数积分:

\int a d x = a x

= \frac{1}{3} u

u = sec (3 t)

代回

= \frac{1}{3} sec (3 t)

解答补常数

= \frac{1}{3} sec (3 t) + C

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