Rewrite the expression as a simplified expression containing one term cos alpha - beta

The given question seem incomplete

Rewrite the expression as a simplified expression containing one term

cos (α + β)cos(β) + sin( α + β)sin(β)

The simplified form of the given expression is cos(α)

Step-by-step explanation:

We are given the expression

cos (alpha + beta)cos(beta) + sin( alpha + beta)sin(beta)

we will proceed by expanding the given expression as

(cos(alpha)cos(beta) - sin(alpha)sin(beta))cos(beta) + (sin(alpha)cos(beta)+cos(alpha)sin(beta))sin(beta)

cos(alpha)cos^2(beta) -sin(alpha)sin(beta)cos(beta) + sin(alpha)cos(beta)sin(beta) + cos(alpha)sin^2(beta)

The two middle terms will cancel each other so we are left with

cos(alpha)cos^2(beta) + cos(alpha)sin^2(beta)

cos(alpha)[cos^2(beta) + sin^2(beta)]

cos(alpha) (1) = cos(alpha)          [cos^2(beta) + sin^2(beta) = 1]

Therefore the simplified form of the given expression is cos(α)

dc=6 square root of 3 and ac is 12 square root 3

c and d

step-by-step explanation:

square root of 3/2 = 18/c

cross multiply to get 18*2=√3*c

36/√3 * √3/√3 = c

c= 36*√3/3

c=12√3

cant

step-by-step explanation: there is no picture