integral of (cos(ln(9t)))/t

解答

\int \frac{cos ( ln ( 9 t ) )}{t} d t

sin (ln (9 t)) + C

求解步骤

\int \frac{cos ( ln ( 9 t ) )}{t} d t

使用换元积分法

= \int \frac{cos ( ln ( u ) )}{u} d u

使用换元积分法

= \int cos (v) d v

使用积分常见定则:

\int cos (v) d v = sin (v)

= sin (v)

代回

= sin (ln (9 t))

解答补常数

= sin (ln (9 t)) + C

\frac{d}{d x} (e^{2 c o s (3 x)})

y^{^{''}} + 4 y^{^{'}} + 4 y = 0, y (0) = 2, y^{^{'}} (0) = - 9

a re a y^{2} - 6 x = 1, x - y = 1

\int - e^{- 2 x} x d x

\int (e) d x