$\frac{\mathrm{A}}{2} \cos \left(\omega \mathrm{t}+\frac{3 \pi}{2}\right)$
$=2 \mathrm{Acos} \omega \mathrm{t}-\mathrm{A} \sin \omega \mathrm{t}-\mathrm{Acos} \omega \mathrm{t}+\frac{\mathrm{A}}{2} \mathrm{sin} \omega \mathrm{t}$
$=$ $Acos\omega t$ $-\frac{\mathrm{A}}{2} \mathrm{sin} \omega \mathrm{t}$
The amplitude of the resultant motion is
$A_{R}=\sqrt{(A)^{2}\left(-\frac{A}{2}\right)^{2}}=\frac{\sqrt{5} A}{2}$
Then the values of $A$ (in $m$) and $T$ (in $sec$) are :
