GATE 1995 Instrumentation

Find $$L\left\{ {{e^{at}}\,\cos \,\omega t} \right\}$$ when $$L\left\{ {\cos \,\,\omega t} \right\} = {s \over {{s^2} + {\omega ^2}}}$$

The laplace transform of a function $$f(t)$$ is defined by $$F\left( s \right) = L\left\{ {f\left( t \right)} \right\} = \int\limits_0^\infty {{e^{ - st}}f\left( t \right)dt.} $$....