[" If "tan alpha=(1)/(7),tan beta=(1)/(3)," then "cos2 alpha" is equal to "],[[" a."sin2 beta," b."sin4 beta]]

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

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 cos2 alpha is equal to adot s in2 beta b.s in4 beta c.s in3 beta d*cos2 beta

If tan alpha=(m)/(m+1) and tan beta=(1)/(2m+1) then alpha+beta is equal to

If tan alpha =m/(m+1) and tan beta =1/(2m+1) , then alpha+beta is equal to

If tan(alpha+beta)=2andtan (alpha-beta)=1 , then tan(2alpha) is equal to