[cos(n+1)alpha*cos(n-1)alpha-sin(n+1)alpha*sin(n-1)alpha=],[" a) "cos2n alphaquad " b) "sin2n alphaquad " c "quad " cos "2 alphaquad " d) "sin2n alpha]

if cos^(2)alpha-sin alpha=(1)/(n) then alpha

( sin(n+1) alpha - sin (n-1)alpha )/( cos (n+1) alpha + 2 cos n alpha + cos (n-1) alpha )=

If A=[cos alpha+sin alpha sqrt(2)sin alpha-sqrt(2)sin alpha cos alpha-sin alpha], prove that =[cos n alpha+sin n alpha sqrt(2)sin n alpha-sqrt(2)sin n alpha cos n alpha-sin n alpha] for all n in N.

cos alpha,-sin alpha,1sin alpha,cos alpha,1cos(alpha+beta),-sin(alpha+beta),1]|

cos alpha,-sin alpha,1sin alpha,cos alpha,1cos(alpha+beta),-sin(alpha+beta),1]|

If Delta = |(cos alpha,- sin alpha,1),(sin alpha,cos alpha,1),(cos (alpha + beta),- sin (alpha + beta),1)| , then

|(cos alpha, sin alpha, cos (alpha+beta)),(- sin alpha, cos alpha, -sin (alpha + beta)),(1,1,1)|=

If (2sin alpha) / ({1 + cos alpha + sin alpha}) = y, then ({1-cos alpha + sin alpha}) / (1 + sin alpha) =

If 2(sin alpha)/(1+cos alpha+sin alpha)=y then value of (1-cos alpha+sin alpha)/(1+sin alpha) is