Prove the following : `(frac(cos11-sin11)(cos11+sin11))=cot56`

Select and write the correct answer from the given alternatives in each of the following: (frac(cos15-sin15)(cos15+sin15))=

Prove the following: frac(cos15^@-sin15^@)(cos15^@+sin15^@)=1/sqrt3

Select and write the correct answer from the given alternatives in each of the following: (frac(cos12-sin12)(cos12+sin12))+(frac(sin147)(cos147)) =

Prove the following: (frac(cos27^@+sin27^@)(cos27^@-sin27^@))=tan72^@

Prove the following: (frac(cos9x-cos5x)(sin17x-sin3x))=(frac(-sin2x)(cos10x))

Prove the following: (frac(sin5x-2sin3x+sinx)(cos5x-cosx))=tanx

Prove the following: (frac(sin3x)(cosx))+(frac(cos3x)(sinx))=2cot2x

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

Prove the following: (frac(cot6A-tan2A)(cot6A+tan2A))=(cos8A)/(cos4A)

Prove the following: (frac(cos2theta)(1+sin2theta))=tan(pi/4-0)