展开 e^tsin(t)U(t-pi/2)

解答

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e^{t} sin (t) U (t - \frac{π}{2})

e^{t} t U sin (t) - \frac{π e ^{t} U sin ( t )}{2}

求解步骤

e^{t} sin (t) U (t - \frac{π}{2})

= e^{t} U sin (t) (t - \frac{π}{2})

使用分配律:

a (b - c) = ab - a c

a = e^{t} sin (t) U, b = t, c = \frac{π}{2}

= e^{t} sin (t) U t - e^{t} sin (t) U \frac{π}{2}

= e^{t} t U sin (t) - \frac{π}{2} e^{t} U sin (t)

化简

e^{t} t U sin (t) - \frac{π}{2} e^{t} U sin (t) : e^{t} t U sin (t) - \frac{π e ^{t} U sin ( t )}{2}

= e^{t} t U sin (t) - \frac{π e ^{t} U sin ( t )}{2}

e x p an d \frac{s + 4}{s ( s ^{2} + 4 s + 104 )}

e x p an d a (e^{b x} + b e^{b x} x)

e x p an d \frac{x ^{2} + 4}{x ^{2}}

e x p an d \frac{8 ( 2 - 2 x ) ^{3}}{3}

e x p an d - 4 (x + 2) - \frac{1}{3} (- 12 x = 3)