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# C3 Trig Help Needed watch

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1. Would someone be able to help me with some C3 Trig?

I have 2 questions

a) √3 sin2(x) + 2sin^2(x) = 1

b) 4 tan2(x) tan(x) =1

Thank you.
2. Have you used your knowledge of double angle identities?

Edit: That probably isn't enough help. For the first one, express in terms of .
3. I have but I'm still stuck with what to do with the 2sin^2 (x) - from a) and the tan(x)- from b)
I have but I'm still stuck with what to do with the 2sin^2 (x) - from a) and the tan(x)- from b)
You have changed the wrong part in a) and you don't need to do anything the tan x in b) except multiply by it.
Would someone be able to help me with some C3 Trig?

I have 2 questions

a) √3 sin2(x) + 2sin^2(x) = 1

b) 4 tan2(x) tan(x) =1

Thank you.
do you mean √3 sin(2x)?

6. (Original post by Goods)
do you mean √3 sin(2x)?

Yes sorry I did.
7. (Original post by Mr M)
You have changed the wrong part in a) and you don't need to do anything the tan x in b) except multiply by it.
In a) I changed the 2sin^2x to (1- cos2x) and got √3 2sinxcosx + (1-cos2x) = 1

Should I now divide by √3 or should I try and simplify?

Thanks
In a) I changed the 2sin^2x to (1- cos2x) and got √3 2sinxcosx + (1-cos2x) = 1

Should I now divide by √3 or should I try and simplify?

Thanks
I have already told you not to replace the sin 2x.

Change it back and subtract 1 from each side.

Now think of a Core 2 identity ...
9. (Original post by Mr M)
I have already told you not to replace the sin 2x.

Change it back and subtract 1 from each side.

Now think of a Core 2 identity ...
I'm sorry I still don't get it, please can you explain in more detail.
I'm sorry I still don't get it, please can you explain in more detail.

etc
11. (Original post by Mr M)

etc
Thank you - I appreciate the help

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Updated: November 20, 2013
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