SOLUTION: I've forgotten how to do this.
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cos(x) = 2
Solve for x.
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As an example from my book:
cos(+/-arctan(2sqrt(6)/5) - i*ln(7) + n*2pi) = 10
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Question 1102550: I've forgotten how to do this.
----
cos(x) = 2
Solve for x.
-------------
As an example from my book:
cos(+/-arctan(2sqrt(6)/5) - i*ln(7) + n*2pi) = 10
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--> cos(x) = 10
x = +/-arctan(2sqrt(6)/5) - i*ln(7) + n*2pi
You can put this solution on YOUR website! There must be an error or omission in the stated problem, because
cos(x) = 2 has no solution, real or complex x.
Here is what happens if you try to solve cos(z) = 2 for z complex:
< definition
Let z=a+bi where a,b are real and i is the imaginary unit
=
using < Euler's equation
=
Now setting this last equation to 2 you get (real part is 2, imaginary part is 0) . Start by setting the imaginary part to 0:
Noting sin(-a) = -sin(a): ==> b = 0
and for the real part:
plugging in b=0, and noting cos(a) = cos(-a): which looks like we are back to the original problem . EXCEPT now 'a' is REAL and we know this has no solution.
