If 1 is added to first 10 natural numbers, then variance of the numbers so obtained is

A random variable X has the following probability distribution

then F(4) =

A differential equation for the temperature 'T' of a hot body as a function of time, when it is placed in a bath which is held at a constant temperature of 32$$^\circ$$ F, is given by (where k is a constant of proportionality)

$$\int_\limits0^{\pi / 4} \log (1+\tan x) d x=$$