Prove that: `cot^2A-tan^2A=4\ cos2A cos e c2A`

Prove that: cot^(2)A-tan^(2)A=4cos2A cos ec2A

cot^(2)A-tan^(2)A=4cot2A cos ec2A

Prove that: (cos 2A cos 3A -cos 2A cos 7A + cos A cos 10A)/("sin" 4A sin 3A - sin 2A sin 5A + sin 4A sin 7A) = cot 6A cot 5A

Prove that :cos ecA-2cot2A cos A=2sin A

Prove :tan^(2)A+cot^(2)A=sec^(2)A cos ec^(2)A-2

Prove that :(1+cot A+tan A)(sin A cos A)=sin A tan A cot A cos A

If A+B+C = pi , prove that : cos2A-cos2B -cos2C = -1+4cosAsinBsinC

In a /_ABC prove that cos2A+cos2B+cos2C=-1-4cos A cos B cos C

Prove that (tan^(2)A-1)/(tan^(4)A-1)=cos^(2)A

Prove that: sec^(2)(tan^(-1)2)+cos ec^(2)(cot^(-1)3)=15 and tan^(2)(sec^(-1)2)+cot^(2)(cos ec^(-1)3)=11