Is there a better way to solve this question? (2 Viewers)

[matchalolz]

I was just wondering if my working out for this question is valid lol and if there's a better way to prove the expression.

 

[integral95]

lol what that doesn't seem valid, you would have to somehow end with the line t1 = t2 (assuming that the question is right)

Yeah just wondering, is this question right?

 

[iStudent]

It's probably just me but I can't see how you could get 2 numbers such that cosx = 5 - 3cosy =/

edit: just realised there's a numerator. lol
edit: are you sure this is the right question?

 

[braintic]

It's probably just me but I can't see how you could get 2 numbers such that cosx = 5 - 3cosy =/

edit: just realised there's a numerator. lol
edit: are you sure this is the right question?

Perhaps I'm being stupid .... but where did the 4 appear from in the RHS expression? (4th line from top)

Is there a 2 missing from the question?

 

[matchalolz]

so sorry i realised i wrote the question wrong when i was copying my working out on to this page >.>
on the top line i left out a 4 on the RHS of the equation, i have no idea how I managed to remember the 4 in the 4th line.

 

[anomalousdecay]

Tbh I had a look at this last night and stared pretty damn hard to understand what happened with that 4t2 and where it came from.....

 

[matchalolz]

yeah, sorry for all the confusion :/ did I do it right though? lol it might just be easier if I ask my teacher when I get back to school