1. Is it true that -log(cosx) = log(secx)? As it says in this answer sheet that my Teacher gave me? If so why?
![Integration Question2.JPG](/data/attachments/24/24570-ab0ffcae07c38ea404748090d426fca8.jpg)
2. Are the proofs that abs(cos(theta)) = cos(theta) necessary in the HSC if so, can someone please explain them?
![Integration Question.JPG](/data/attachments/24/24569-55a698b74297b2eea1971d5ac0b5ffed.jpg)
3. I noticed in the Standard Integrals sheet for Ext 2 2014 there was no cos^-1 integral, and I assumed this is because cos^-1 = - sin^-1 but apparently this isn't true (according to wolfram alpha) so Im not sure whether to just leave the answer as - sin^-1 or if there is a proof I need to do?
Cheers, everyone have a good holiday!
![Integration Question2.JPG](/data/attachments/24/24570-ab0ffcae07c38ea404748090d426fca8.jpg)
2. Are the proofs that abs(cos(theta)) = cos(theta) necessary in the HSC if so, can someone please explain them?
![Integration Question.JPG](/data/attachments/24/24569-55a698b74297b2eea1971d5ac0b5ffed.jpg)
3. I noticed in the Standard Integrals sheet for Ext 2 2014 there was no cos^-1 integral, and I assumed this is because cos^-1 = - sin^-1 but apparently this isn't true (according to wolfram alpha) so Im not sure whether to just leave the answer as - sin^-1 or if there is a proof I need to do?
Cheers, everyone have a good holiday!