" (v) "2cot A=cot(A)/(2)-tan(A)/(2)" ."quad =3tan3 alpha" ."

tan A-cot A=-2cot2A

If A+B+C=pi, show that : tan.(A)/(2)tan.(B)/(2)+tan.(B)/(2)tan.(C)/(2)+tan.(C)/(2)tan.(A)/(2)=1 Hence deduce that : cot.(A)/(2)+cot.(B)/(2)+.cot.(C)/(2)=cot.(A)/(2).cot.(B)/(2)tan.(C)/(2) .

If A+B+C=pi , prove that (a) tan 3A+tan3B+tan3C=tan3A tan 3B tan 3C (b) cot""(A)/(2)+cot""(B)/(2)+cot""(C)/(2)=cot""(A)/(2)cot""(B)/(2)cot""(C)/(2)

If cosx-sinalphacotbetasinx=cosa , then the value of tan(x/2) is (a) -tan(alpha/2)cot(beta/2) (b) tan(alpha/2)tan(beta/2) (c) -cot((alphabeta)/2)tan(beta/2) (d) cot(alpha/2)cot(beta/2)

If cosx-sinalphacotbetasinx=cosa , then the value of tan(x/2) is (a) -tan(alpha/2)cot(beta/2) (b) tan(alpha/2)tan(beta/2) (c) -cot((alphabeta)/2)tan(beta/2) (d) cot(alpha/2)cot(beta/2)

If 2tan A+cot A=tan B then cot A+2tan(A-B)=

If 2tan A+cot A=tan B then cot A+2tan(A-B)=

Prove that cotA-tanA=2cot2A and deduce that tan alpha+2tan2alpha+4tan4alpha+8cot8alpha=cot alpha

If cosx-sinalphacotbetasinx=cosa , then the value of tan(x/2) is -tan(alpha/2)cot(beta/2) (b) tan(alpha/2)tan(beta/2) -cot((alphabeta)/2)tan(beta/2) (d) cot(alpha/2)cot(beta/2)

Three positive acute angles alpha, beta and gamma satisfy the relation tan. (beta)/(2)=(1)/(3)cot.(alpha)/(2)and cot.(gamma)/(2)=(1)/(2)(3tan.(alpha)/(2)+cot.(alpha)/(2)) . Then, the value of alpha+beta+gamma is equal to