Verify: 2Arctan 1/2 = Arctan 4/3 ?

1 Answer
Nov 17, 2017

2arctan(1/2)=arctan(4/3)

Explanation:

Set u=Arctan(1/2), so tanu=1/2

Hence tan2u

=(2tanu)/[1-(tanu)^2]

=2*(1/2)/[1-(1/2)^2]

=1/(3/4)

=4/3

Thus, 2arctan(1/2)=arctan(4/3)