Prove the following:`4cosxcos(pi/3+x)cos(pi/3-x)=cos3x`

Prove the following: cos(pi/4+x)+cos(pi/4-x)=sqrt2cosx

Prove the following: cos(3pi/2+x)cos(2pi+x)[cot(3pi/2-x)+cot(2pi+x)]=1

Prove the following: (frac(cos(pi+x)cos(pi-x))(sin(pi-x)cos(pi/2+x)))=cot^2x

Prove the following: cos(pi/4-x).cos(pi/4-y)-sin(pi/4-x).sin(pi/4-y)=sin(x+y)

Prove the following: cos(pi/2-x)cos(pi/2-y)-sin(pi/2-x)sin(pi/2-y)=-cos(x+y)

Using tables evaluate the following: cos^2 0+cos^2 (pi/6)+cos^2 (pi/3)+cos^2 (pi/2)

Prove the following: sin(pi/6+A).cos(pi/3-B)+sin(pi/3-B).cos(pi/6+A)=cos(A-B)

Select and write the correct answer from the given alternatives in each of the following: cos(3pi/4+x)-cos(3pi/4-x) =………

cos((3pi)/4+x)-cos((3pi)/4-x)=

Prove the following: (1+cos (pi/8))(1+cos((3pi)/8))(1+cos ((5pi)/8))(1+cos ((7pi)/8))=1/8