(d^2)/(dx^2)((x)(5xcos(3x)+8xsin(3x)))

解答

\frac{d ^{2}}{d x ^{2}} ((x) (5 x cos (3 x) + 8 x sin (3 x)))

- 45 x^{2} cos (3 x) - 72 x^{2} sin (3 x) - 60 x sin (3 x) + 96 x cos (3 x) + 10 cos (3 x) + 16 sin (3 x)

求解步骤

\frac{d ^{2}}{d x ^{2}} ((x) (5 x cos (3 x) + 8 x sin (3 x)))

\frac{d}{d x} (x (5 x cos (3 x) + 8 x sin (3 x))) = - 15 x^{2} sin (3 x) + 24 x^{2} cos (3 x) + 10 x cos (3 x) + 16 x sin (3 x)

= \frac{d}{d x} (- 15 x^{2} sin (3 x) + 24 x^{2} cos (3 x) + 10 x cos (3 x) + 16 x sin (3 x))

\frac{d}{d x} (- 15 x^{2} sin (3 x) + 24 x^{2} cos (3 x) + 10 x cos (3 x) + 16 x sin (3 x)) = - 45 x^{2} cos (3 x) - 72 x^{2} sin (3 x) - 60 x sin (3 x) + 96 x cos (3 x) + 10 cos (3 x) + 16 sin (3 x)

= - 45 x^{2} cos (3 x) - 72 x^{2} sin (3 x) - 60 x sin (3 x) + 96 x cos (3 x) + 10 cos (3 x) + 16 sin (3 x)

e x p an d sin (k (t - k u))

e x p an d 6.7 x + 2.8 x

e x p an d 2 \cdot \frac{1 0 ^{2} \cdot 3 \cdot 2 ^{4}}{2 - 3} - (5^{2} \cdot 2 - 7 \cdot 3)

e x p an d x H (y - 1)

e x p an d \frac{( ( x ^{2} + 3 ) ^{2} )}{6 x}