Evaluate cos[2arctan(2)]
Need step by step for this one. Thanks
cos(arctan(2)) = 1/√5
cos2x = 2cos^2(x)-1
so,
cos(2arctan(2)) = 2*1/5 - 1 = -3/5
Need step by step for this one. Thanks
cos2x = 2cos^2(x)-1
so,
cos(2arctan(2)) = 2*1/5 - 1 = -3/5