" 27.If "sin alpha=(4)/(5)" and "cos beta=(5)/(13)," prove that one value of "cos(alpha-beta)/(2)=(8)/(sqrt(65))

If cos alpha=(4)/(5) and cos beta=(5)/(13), prove that (cos(alpha-beta))/(2)=(8)/(sqrt(65))

If sin alpha=(3)/(5) and cos beta=(9)/(41) find the value of sin(alpha-beta) and cos(alpha+beta)

If sin alpha=4/5 and cos beta =5/13, prove that cos ((alpha-beta)/2)=8/sqrt 65.

sin alpha+sin beta=(1)/(4) and cos alpha+cos beta=(1)/(3) The value of cos(alpha+beta) is

sin alpha+sin beta=(1)/(4) and cos alpha+cos beta=(1)/(3) The value of cos(alpha+beta) is

If cos alpha=4/5 and cos beta =5/13, prove that cos (alpha-beta)/2=28/65.

Le alpha and beta be such that pi

Let alpha, beta be such that pi lt alpha- 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

If cos alpha+cos beta=(1)/(3) and sin alpha+sin beta=(1)/(4) prove that cos[(alpha-beta)/(2)]=+-((5)/(24))

If sin(alpha+beta)=(4)/(5), sin(alpha-beta)=(5)/(13) , find the value of tan 2alpha :