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# Need help with C3 TRIG. Homework!!! watch

1. Alright, the question is to solve this equation.
(3cos(2x))/(cos(2x)+1) = 2 ( tan(x) + 1 )

I've tried for ages and i'm not really obtaining any solutions that when I put back in the equation really satisfy it. Can anyone help?

Any help, is much appreciated. Tyy
2. (Original post by akash3141)
Alright, the question is to solve this equation.
(3cos(2x))/(cos(2x)+1) = 2 ( tan(x) + 1 )

I've tried for ages and i'm not really obtaining any solutions that when I put back in the equation really satisfy it. Can anyone help?

Any help, is much appreciated. Tyy
Bear in mind that . Also it'll help to see your previous attempts.

Spoiler:
Show

also tagging to move to the right section Sonechka Lemur14
3. Also, as you have a tan(x) term, the other identity:

may be useful here as well as well as the identity provided by _gcx above.
4. (Original post by simon0)
Also, as you have a tan(x) term, the other identity:

may be useful here as well as well as the identity provided by _gcx above.
I got cos(x)[2cos(x)-4sin(x)] = 3
idk if it's right or not but either way, I have no clue what to do after this, lol?
5. (Original post by akash3141)
I got cos(x)[2cos(x)-4sin(x)] = 3
idk if it's right or not but either way, I have no clue what to do after this, lol?
- The equation is equaivalent to the question but not what I had in mind.

- Starting again, for the left-hand equation try:
1) My substitution for cos(2x) in the numerator,
2) _gcx's substitution for cos(2x) in the denominator.

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Updated: November 3, 2017
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