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Determine which one of the following is not equivalent to the expression $\cos^{2}x-\cos^{2}x\cdot \sin^{2}$.

$\sin^{2}x$

$\cos^{4}x$

$\cos^{2}x(\cos^{2}x)$

$-\cos^{2}x(\sin^{2}x-1)$

$\cos^{2}x(1-\sin^{2}x)$