If `alpha+beta=90^@`, show that the maximum value of `cos alpha cos beta` is `(1)/(2)`

If alpha+beta=90^(0) ,show that the maximum value of cos alpha.cos beta is (1)/(2)

If alpha + beta = 90^0 , show that the maximum value of cos alpha.cos beta is 1/2 .

If alpha+beta=pi/2 , then the maximum value of cosalpha cos beta is:

If alpha+beta=90^(0) ,then the minimum and maximum values of cos alpha*cos beta are (A) -1/3 and 1/3 (B) -1 and 1 (C) -1/4 and 1/4 (D) -1/2 and 1/2

If alpha+beta=90^@ , and alpha=2 beta , then the value of 3 cos^2 alpha-2 sin^2 beta is: यदि alpha+beta=90^@ , और alpha=2 beta , तो 3 cos^2 alpha-2 sin^2 beta का मान ज्ञात करें:

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+beta=90^@ and alpha=2beta , then the value of 3cos^2alpha-2sin^2beta is equal to:

If cos alpha + cos beta = 0 = sin alpha + sin beta, then value of cos 2 alpha + cos 2 beta is