Help with Q6 from the C4 exam?

In question 6! i cant remember the exact question but think it was:

u = 4sin^2(x)

prove = integral (4/(1-4x)^1/2 is same as (k integral sin^2(u)) where you must find k.

the prove that the integral = k (integral) sin^2x i got 1/8 (integral) sec^2x.

Where did i go wrong and how many marks would i have got for the follow up question if i used k= 1?8 instead of k =8?

(edited 7 years ago)

Reply 1

Zacken

Original post by twigface

In the prove that the integral = k (integral) sin^2x i got 1/8 (integral) sec^2x.

Where did i go wrong and how many marks would i have got for the follow up question if i used k= 1?8 instead of k =8?

Your question doesn't make sense as it stands, please edit and clarify.

Reply 2

WillRose

Original post by twigface

you mean lambda not k right? all the method marks minus accuracy if you did it right

Reply 3

twigface

Original post by WillRose

you mean lambda not k right? all the method marks minus accuracy if you did it right

yeah i think so.

do you remember what the question was?

Reply 4

twigface

Original post by Zacken

Your question doesn't make sense as it stands, please edit and clarify.

ok written out the question

Reply 5

twigface

Original post by twigface

yeah i think so.

do you remember what the question was?

so probably 4/5?

Reply 6

twigface

Original post by WillRose

you mean lambda not k right? all the method marks minus accuracy if you did it right

actually refresh if you've seen this as i have edited

Reply 7

Dieselblue

Not sure how you got sec^2T

The 8 came from the dx/dT where T = theta
I can't really remember the question but I remember something along the lines of tanx*8sinx*cosx I can't remember what was squared and what wasn't