The area enclosed between the curves $${y^2} = 4x\,\,$$ and $${{x^2} = 4y}$$ is

The distance between the origin and the point nearest to it on the surface $$\,\,{z^2} = 1 + xy\,\,$$ is

If three coins are tossed simultaneously, the probability of getting at least one head is

The standard deviation of a uniformly distributed random variable $$b/w$$ $$0$$ and $$1$$ is