Recent content by whyyie

I have try another method of using integrating factor for the second order DE. But still I think there is nothing related with the word "hence" from the first part. I have double check the answer, the answer satisfy the equation. Is the word "hence" means continue from the answer from the...

Integrate that will get 2x + sinh (2x) with c = 0. i don't think that we can compare.

Always remember to multiply by the conjugate. [PLAIN]http://img337.imageshack.us/img337/1976/50453339.jpg

Yup. By differentiating 2x+sinh(2x) we will be able to get 4*cosh(x)^2. Also, the second order DE above is actually the derivatives of the first order DE. But I didn't manage to figure out how to use the relationship between the first and second order DE to solve the question.

Well, I am not sure whether this can be consider as proving. Can someone assure me? First we assume e^x = x. then we sketch 2 graphs: y= e^x y=x From the graph, e^x > x for all x in R. Therefore, e^x > x for all x in R.

http://img213.imageshack.us/img213/7402/30788730.jpg This questions consists of a total of 13 marks - 6 marks for the first order DE - 7 marks for the second order DE I attempted the solution as below. I could solve the second order DE using normal method but when I think again the word...