2006 HSC 4u issue (1 Viewer)

[hayabusaboston]

I believe there was a misprint for question 7 b), I think it should be In=sec^n-2......+(n-2)/(n-1)In+2, but they have In-2 ON THE ACTUAL PAPER, double checked 10 times and I cant see where im wrong for getting In+2, can someone show how to get In-2 on the end bit?

 

[iJimmy]

Urgent assistance BUMP x 1000000

 

[braintic]

It is correct. See Lee's solutions:

View attachment 2006 7bi.pdf

 

[hayabusaboston]

It is correct. See Lee's solutions:

View attachment 28739

but isnt sec^n-2 differentiated, (n-2)sec^(n-1) TIMES secxtanx? Since I thought sec differentiated was secxtanx? then this becomes
(n-2)sec^(n-1)secxtanx, its sec^n-1+1 with the powers, so shouldnt that be (n-2)sec^(n)xtanx, times v=tanx and u get (n-2) sec^n.tan^2, change to sec^2-1 etc... but u see my point?

 

[seanieg89]

but isnt sec^n-2 differentiated, (n-2)sec^(n-1) TIMES secxtanx? Since I thought sec differentiated was secxtanx? then this becomes
(n-2)sec^(n-1)secxtanx, its sec^n-1+1 with the powers, so shouldnt that be (n-2)sec^(n)xtanx, times v=tanx and u get (n-2) sec^n.tan^2, change to sec^2-1 etc... but u see my point?

what is (n-2)-1?

 

[hayabusaboston]

what is (n-2)-1?

JEEZUS EPIC SILLIE MISTAKE

lol


I SEE THANKS SEANIEG