Question

trig help guys!

Answer 1

i cat read the first one very well is it

cos^2x cc^2x + cos^2x sec^2x = csc"2x ?

Answer 2

thats csc^2 x not cc^2 x

Answer 3

@cwrw238 it's
cos^2x csc^2x+cos^2x+sec^2x=csc^2x

Answer 4

ok
lets try converting LHS to sin's and cos:

cos^2x * 1 / sin^2x + cos^2x / cos^2 x
= tan^2 x + 1

csc^2 x = 1 + tan^2 x is a known identity

so the answer to this one is it is an identity and we have proved it as above

Answer 5

I think you have inserted a '+' in your last post

Answer 6

@cwrw238 ooh yes it's wrong, it does not have a plus sign, your right

Answer 7

do you follow the proof i gave?

Answer 8

i'm looking over it, why did you put a "*"? I know it's multiply, but why..

Answer 9

csc = 1 / sin
I multiplied by 1 / sin

Answer 10

@cwrw238 ooooh okay thank you!

Answer 11

ooh - i made 1 mistake for tan^2 x read cot^2 x

the identity is csc" x = 1 + cot^2 x

Answer 12

the third one is a bit tricky

there is a known identity tan( A + B) = tanA + tan B
-----------
1 + tan A tan B

Answer 13

now since cot (A + B) = 1 / tan(A + B)
inverting the above
cot(A + B) = 1 + tan A tan B
-------------
tan A + tan B

so this is not correct - not an identity

Answer 14

- that makes no difference to the proof - its still correct - just substitute cot where you see tan.

Answer 15

@cwrw238 I put not an identity

Answer 16

hold on you put not an identity for which one?

Answer 17

@cwrw238 for3

Answer 18

thats correct

correct