If `alpha,beta` satisfy equation `sin2alpha = cos2beta`, then possible value(s) of expression `2/pi[alpha-beta-pi/4]` is/are

if alpha and beta satisfy sin alpha cos beta=-(1)/(2), then the greatest value of 2cos alpha sin beta is

If alpha and beta satisfy sinalpha cos beta=-1/2 , then the greatest value of 2cos alpha sin beta is ……….

If alpha and beta satisfy sin alpha cos beta=-((1)/(2)), then the greatest value of 2cos alpha sin beta is

If 0 lt alpha, beta lt pi and they satisfy cos alpha + cosbeta - cos(alpha + beta)=3/2

If 0 lt alpha, beta lt pi and they satisfy cos alpha + cosbeta - cos(alpha + beta)=3/2

If alpha, beta be such that pi < alpha- beta < 3 pi . If sin alpha +sin beta= -21/65 and cos alpha + cos beta = -27/65 , then the value of cos frac (alpha-beta)(2) is :

Let alpha, beta be such that pi lt alpha lt beta lt 3pi, if sin alpha + sin beta =- (21)/(65) and cos alpha + cos beta =(27)/(65), then the value of cos ""(alpha - beta)/(2) is-

Let alpha , beta be such that pi lt alpha - beta lt 3 pi . If sin alpha + sin beta =-(21)/(65) and cos alpha + cos beta =-(27)/(65) , then the value of cos""(alpha - beta )/(2) is