MAths P1 Trigonometry help!

[Saturation]

Question 2:
http://www.xtremepapers.me/CIE/Internat ... _qp_12.pdf

The mark scheme doesnt make sense! I would like to know how you do it starting from the right hand side!
Thanks!

 

[Zishi]

It's way too easy if you try to do it from left hand side. 8)

 

[YuriGagarin]

rhs= tan^2x.sin^2x
= {sin^2x(1-cos^2x)}/cos^2x
= (sin^2x-sin^2x.cos^2x)/cos^2x
= tan^2x-sin^2x

hope u get it

 

[Saturation]

Ahk! I'm sorry, I mean LEFT hand hand side! :fool: How do you do it??

 

[soumayya]

tan^2 x − sin^2 x ≡ tan^2 x sin^2 x

L.H.S:
tan^2 x − sin^2 x = sin^2 x /cos^2 x - sin^2 x
= [sin^2 x - sin^2 x cos^2 x]/ cos^2 x
= [sin^2 x (1 - cos^2 x)] / cos^2 x
= [sin^2 x * sin^2 x ] / cos^2 x
= sin^2 x tan^2 x

 

[Mortal9090]

Ahk! I'm sorry, I mean LEFT hand hand side! :fool: How do you do it??

Dude, basic rule.. start from the more difficult looking side.

in P1, we only use basic identities, make sure you hand write them on a paper, then visualize, so that you could recall it whenever necessary, however you'll find most on mf9.

fyi i did the same and i found them very helpful