cos(2tan^(-1)(1)/(2))=?

Show that cos(2Tan^(-1).(1)/(7))=sin(2Tan^(-1).(3)/(4))

Find the value of : sin (sin ^(-1) ""(1)/(3) + sec ^(-1) 3)+cos( tan^(-1) ""(1)/(2) + tan ^(-1) 2)

cos(tan^(-1)((1)/(3))+tan^(-1)((1)/(2)))=

cos(tan^(-1)((1)/(3))+tan^(-1)((1)/(2)))=

sin(sin^(-1)((1)/(3))+sec^(-1)(3))+cos(tan^(-1)(1/2)+tan^(-1)2) =

The value of sin(sin^(-1) (1/3) + sec^(-1) 3)+ cos(tan^(-1) (1/2) + tan^(-1) 2) is……….

Which of the following is/are correct? tan[cos^(-1)(4)/(5)+tan^(-1)(2)/(3)]=(17)/(6)cos[tan^(-1)(1)/(3)+tan^(-1)(1)/(2)]=(1)/(sqrt(2))cos2tan^(-1)((1)/(3))+cos(tan^(-1)2sqrt(2))=(14)/(15)cos[2cos^(-1)(1)/(5)+sin^(-1)(1)/(5)]=-(2sqrt(6))/(6)

If cos(2tan^(-1)x)=1/2 , then the value of x is ___

Let cos(2 tan^(-1) x)=1/2 then the value of x is