• We are pleased to announce that the winner of our Feedback Prize Draw for the Winter 2024-25 session and winning £150 of gift vouchers is Zhao Liang Tay. Congratulations to Zhao Liang. If you fancy winning £150 worth of gift vouchers (from a major UK store) for the Summer 2025 exam sitting for just a few minutes of your time throughout the session, please see our website at https://www.acted.co.uk/further-info.html?pat=feedback#feedback-prize for more information on how you can make sure your name is included in the draw at the end of the session.
  • Please be advised that the SP1, SP5 and SP7 X1 deadline is the 14th July and not the 17th June as first stated. Please accept out apologies for any confusion caused.

CT8 April 2012 Q8 (iii) - Question 18 in revision notes

A

Adithyan

Member
Can someone help me understand the how the differentiation is done?
 
An easier way to do this is to note that, if you have something like Integral{0,x} f(t)dt, this is just the integral of the function f(x). Eg, if f(t) = t^2, this would just be x^3/3. So, if you differentiate it, you'll just get back to the function f(x).

Here, Integral{K,Infinity} D0(a)da is the same as -Integral{Infinity,K} D0(a)da, and the letters are different. (We have K instead of x, a instead of t, D0 instead of f and Infinity instead of 0.) But, if you differentiate wrt K, you'll just get -D0(K), as before.

This was another very difficult question!
 
You must log in or register to reply here.
Back
Top