Timothy.Siu
Prophet 9
yeah ok, i'll be careful
lulsTrebla said:omg time warp due to clock changes!!! LOL
Well for the first one:jm01 said:Hello,
I have a question with this. I'd appreciate it if you could show steps.
Evaluate:
1) cos(2sin-1(sqrt(3))/2)
1)jm01 said:Thanks for that. I have a few more questions. Would appreciate if you could assist me.
Show that:
1) tan-14 - tan-1(3/5) = pi/2
2) tan-1(5/12) + cos-1(5/13) = pi/2
Evaluate the without aid of tables:
3) cos[sin-1(5/13)+sin-1(4/5)]
4) sin[2tan-1(4/3)]
Thanks again!
I used a pre-existing result of compound angles out of the blue.jm01 said:Thank you Trebla,
Just one quick question though, in Q1 where did you get (x - π/4) from?
Doesn't that mean you've assumed the result you are trying to prove?Timothy.Siu said:lol, for those ones are u allowed to just tan both sides? hmm coz thats wat i did when i did them but i'm sure if ur allowed to.
In that case, as long as you go from LHS --> RHS without assuming the result, it should be fine.Timothy.Siu said:probably,
like for this one
the Q is 1) tan<sup>-1</sup>4 - tan<sup>-1</sup>(3/5) = pi/4
i say, tan[tan<sup>-1</sup>4 - tan<sup>-1</sup>(3/5)]=[working out]=tan pi/4
and , then i say therefore tan<sup>-1</sup>4 - tan<sup>-1</sup>(3/5) = pi/4