00:01
The pdf of the random variable x is given by 2 into x plus 3 divided by 7, 0 less than x less than 1 and 0x.
00:16
There is a random variable defined as 4x square plus 3, we need to find the variance of this random variable.
00:24
So, variance of g of x is variance of 4x square plus 3, which i can write it as variance of 4x square plus variance of three.
00:41
Remember, variance of ax plus b is actually a square times variance of x where they are constants.
00:52
So using the same logic, i can write this as 16 variants of x squared plus variance of three, zero.
01:00
So our ultimate aim is to find variance of x squared, but variance of x squared by definition is expectation of x power 4 minus expect expectation of x square the whole square.
01:17
So let's find expectation of x power 4.
01:19
It is integration to 0 to 1 x power 4 into 2 into x plus 3 by 7 dx.
01:28
So let's calculate this...