Negation of the statement ' Horses have wings if and only if crows have tails. ' is

A plane which is perpendicular to two planes $2 x-2 y+z=0$ and $x-y+2 z=4$, passes through $(1,2,1)$. The distance of the plane from the point $(2,3,4)$ is

If $\log (x+y)=\sin (x+y)$, then $\frac{\mathrm{d} y}{\mathrm{~d} x}$ is

$$\int \sqrt{\mathrm{e}^x-1} \mathrm{dx}=$$