I got -1/2 instead of -1/4, due to there being an extra x2 The link to the answer is here:https://imgur.com/gallery/UJIcLIW Can someone explain why there is an extra x2???
I got -1/2 instead of -1/4, due to there being an extra x2 The link to the answer is here:https://imgur.com/gallery/UJIcLIW Can someone explain why there is an extra x2???
Can I see your working, and the original question please?
I got -1/2 instead of -1/4, due to there being an extra x2 The link to the answer is here:https://imgur.com/gallery/UJIcLIW Can someone explain why there is an extra x2???
Because they have applied the chain rule twice and I suspect you have not.
I would be able to explain better if I knew the original question, but to find the derivative of some functions you'll need to do it twice. Did you get my PM?
The question is 2b and I have also attached my working out.
Use substitution, where u = cot(2x), so u(1)(x) (first derivative) = -2cosec2(2x), and dx = -1/2*sin2(2x). Substituting this in gives the integral of -0.5u, which is -u2/4. Undoing the substitution gives -1/4* cot2(2x) + C as required.
Use substitution, where u = cot(2x), so u(1)(x) (first derivative) = -2cosec2(2x), and dx = -1/2*sin2(2x). Substituting this in gives the integral of -0.5u, which is -u2/4. Undoing the substitution gives -1/4* cot2(2x) + C as required.