00:01
In this problem, the probability density function, okay, probability density function of the variable x.
00:09
So the probability density function, in short, we can test pdf.
00:14
It is given as f of x is equal to e power minus 2x plus half of e power minus x when 0 less than x less than infinity and zero otherwise, right? now we will take e power minus 2 x as y so if this function is a monotonic decreasing function so because we are considering in the left hand side so it is monotonic decreasing function so from this we can take e power 2x is equal to 1 by y so now from this while simplifying what is by taking log on both sides we'll get 2x is equal to log of 1 by y from this x equal to half times log of 1 by y.
01:01
Okay then from this we have to differentiate with respect to y.
01:05
So d x by dye is equal to 1 by 2 times log of 1 by y will give you so upon simplification we can read it as 1 by 2 times log of y inverse which is equal to minus 1 by 2 log y so differentiate this with respect to x y so we will get d x by d y is equal to minus 1 by 2 times 1 by y which is equal to minus 1 by 2y.
01:30
Then from this we have to find the probability density function of y.
01:36
Therefore, f of y is equal to d x by dy multiplied by f of x, which is equal to, so dx by dy is 1 by 2y, multiplied by 2y, multiplied by f of x, we can write in terms of y.
01:52
So, so y plus 1 by 2 times e power 1 by 2 log y...