Sin(x^2 y^2)/(x^2 y^2) 175813-F x y x 2 y 2 sin 1/ x 2 y 2
$$ \begin{align} \sin(xiy) &= \sin x \cos (iy)\cos x \sin(iy) \\ &= \sin x \cosh y i \cos x \sinh y \end{align} $$ $$ \begin{align} \sin(xiy)^2 &= (\sin x \cosh y)^2 (\cos x \sinh y)^2 \end{align} $$ Now you can get rid of the cosines knowing that $\cos^2 x \sin^2 x = 1$ and that $\cosh^2 x \sinh ^2 x = 1$ You can take it from there