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# How do I solve cos(x)=2? watch

1. How would I solve ?
2. You don't
3. (Original post by Cryptokyo)
How would I solve ?
I don't think there is a solution because cos(x) can't be bigger than 1 or smaller than -1
4. (Original post by Cryptokyo)
How would I solve ?
Use

cos(x+iy) = cosx coshy - i sinx sinhy
5. In which domain?
6. The function cosx only varies between -1 and 1. There is no number that equals arccos(2).
7. (Original post by RichE)
Use

cos(x+iy) = cosx coshy - i sinx sinhy
Thank you!

Thank you to you too!
8. Don't really know what people would do without you TeeEM
I think this stuff is a bit beyond my level (A2 Maths) XD
9. (Original post by CheeseIsVeg)
You don't
(Original post by anosmianAcrimony)
The function cosx only varies between -1 and 1. There is no number that equals arccos(2).
10. (Original post by RDKGames)
11. Use the exponential definition of cos, you get a quadratic in e^x.
12. (Original post by anosmianAcrimony)
The function cosx only varies between -1 and 1. There is no number that equals arccos(2).
The solution is more complex than you realise...

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