How do you evaluate #arctan(1/2)#?

1 Answer
Alan P.
Jun 1, 2015

The #arctan(1/2)# is the angle #theta# such that #tan(theta) = 1/2#

We can imagine such an angle in the first quadrant as being part of a right-triangle with opposite side #=1#, adjacent side #=2#, and hypotenuse #=sqrt(5)#.

Unfortunately this is not one of the standard angles and the only way (as far as I can tell) to evaluate it is to use a calculator (or something similar) to look-up:

#arctan(1/2) = 0.463648 " radians" = 26.56505^@#

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