Re: Maths

Posted by duck on Dec 21, 2011; 4:03pm
URL: http://discussion-forum.276.s1.nabble.com/Maths-tp7111879p7115611.html

Hi Vasudha.. :)

i interpreted the question in a diff way..

i took f(x)= cos(x) => f'(x)= -sin x
We know, f(-x)=cos(x) => f'(-x) = - sin x
{since, cos x is an even funtion}
we can see f'(x)= f'(-x) = -sin x,  for all x.. so the initial condition is satisfied.
In this way, you can rule out rest of the options.

However, I think it depends on the way we interpret the question.