Question

Trig Identities
Proof:
\[\frac{ cosx-sinx }{ cosx+sinx }=\sec2x-\tan2x\]

Answer 1

Please help! :(

Answer 2

cos = ?
sin = ?

Answer 3

I'm not sure what you mean?

Answer 4

trig identities
sin cos tan properties
tan = sin /cos
sin = ?
cos = ?

Answer 5

sin=y/r
cos=x/r

Answer 6

o^_^o \[\rm \sin = \frac{ 1 }{ \csc }\] \[\rm \cos = \frac{ 1 }{ \sec }\]

Answer 7

ooh...

Answer 8

solve L.H.S replace
cos by 1/sec
and sin by 1/csc

Answer 9

that works nicely, there is a shortcut though.. multiply top and bottom by the conjugate of denominator : `cosx - sinx`

Answer 10

and recall the identity : \[\cos^2x-\sin^2x=\cos(2x)\]

Answer 11

okay so right
is that
\[\large\rm \sec^2 x - \tan^2x ~~or~ \sec(2x) - \tan (2x)\]
square or 2x ?

Answer 12

2x @Nnesha
Sorry, I got logged out suddenly and had some difficulty logging back on.

Answer 13

@ineedhelpnowplz