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$\displaystyle L\left[\sin{4\ u}\right]=\frac{4}{s^2+4^2} \\[2ex] \displaystyle L\left[ u\sin{4 u}\right]=\left(-1\right)\frac{d}{ds}\left(\frac{4}{s^2+4^2}\right) \\[2ex] \displaystyle =-4.\ \frac{-1}{(s^2+4^2)^2}.2s \\[2ex] \displaystyle =\frac{8s}{(s^2+4^2)^2} \\[2ex] $
$\displaystyle L\left[\ {ue}^{-3u}sin{4\ u}\right]=\frac{8\left(s+3\right)}{[({s+2)}^2+4^2]^2}…first\ shifting\ property \\[2ex] \displaystyle L\left[\int_0^t\ {ue}^{-3u}\sin{4udu}\right]=\frac{1}{s}.\frac{8\left(s+3\right)}{[(s^2+4s+4+16]^2} \\[2ex] \displaystyle =\frac{8\left(s+3\right)}{s[(s^2+4s+20]^2} \\[2ex] \displaystyle -L\left[\ H.\left(t-\frac{3\pi{}}{2}\right)\right] \\[2ex] \displaystyle =e^{-\frac{\pi{}s}{2}}\ L\left[\ sin\left(t+\frac{\pi{}}{2}\right)\right]-e^{-\frac{3\pi{}s}{2}}.\frac{1}{s}\ \\[2ex] \displaystyle =e^{-\frac{\pi{}s}{2}}L\left[\ cost\right]-e^{-\frac{3\pi{}s}{2}}.\frac{1}{s} \\[2ex] \displaystyle =e^{-\frac{\pi{}s}{2}}.\frac{s}{{\ s}^2+1}-e^{-\frac{3\pi{}s}{2}}.\frac{1}{s} \\[2ex] \displaystyle =\ \frac{{se}^{-\frac{\pi{}s}{2}}}{\ \ s^2+1}-\frac{e^{-\frac{3\pi{}s}{2}}}{s} \\[2ex]$

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