" 8.If "tan alpha=1/7" and "tan beta=1/3," then "cos2a" is "

If tan alpha=(1)/(7) and tan beta=(1)/(3) , then cos2 alpha is equal to

If tan alpha=(1)/(7), tan beta=(1)/(3), then cos 2 alpha is equal to

If tan alpha=(1)/(7),tan beta=1/3, then cos2 alpha is equal to adot s in2 beta b.s in4 beta c.s in3 beta d*cos2 beta

tan alpha=(1)/(7),tan beta=(1)/(3), then cos2 alpha=

If tan alpha = 1/3 and tan beta = 1/2 , then: tan(alpha + beta) =

If tan alpha=(1)/(3) and tan (beta)=(1)/(2) then tan (alpha+beta)=

If" " n tan alpha = (n+1) tan beta " then show that", tan (alpha - beta) = (sin 2 beta)/(2n + 1 - cos2 beta).

If tan^(2) alpha = 1 + 2 tan^(2) beta, "prove that ," cos 2 beta = 1 + 2 cos 2 alpha

If tan^2 alpha = 1 + 2 tan^2 beta , show that cos2 beta = 1 + 2cos 2alpha .