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\[ if \ L[J_0 (t) ] = \dfrac {1}{\sqrt{s^2+1}} \] prove \[ \int^\infty_0 e^{-6t} t J_0 (4t) dt = 3/500 \]
1 Answer
| written 4.6 years ago by |
$ L[J_0(8t)]=\dfrac{1}{8}.\dfrac{1}{\sqrt{\big[\dfrac{s}{8}\big]^2+1}}$
$\therefore L[J_0(8t)]=\dfrac{1}{\sqrt{s^2+64}}$
$ L[tJ_0(8t)]=(-1)^1.\frac{\mathrm{d}\dfrac{1}{\sqrt{s^2+64}}}{\mathrm{d}s}$
$\therefore L[tJ_0(8t)]=(-1).\dfrac{(\sqrt{s^2+64})(0)-(1)\big(\dfrac{2s}{2\sqrt{s^2+64}}\big)}{(\sqrt{s^2+64})^2}$
$\therefore L[tJ_0(8t)]=\dfrac{s}{(s^2+64)(\sqrt{s^2+64})}$
$\therefore \int_{0}^{\infty}e^{-6t}tJ_0(8t)dt=\dfrac{s}{(s^2+64)(\sqrt{s^2+64})}$...(By definition)
$\therefore \int_{0}^{\infty}e^{-6t}tJ_0(8t)dt=\dfrac{3}{500}$