If `A+B+C=pi`, prove that : `(tanA+tanB+tanC) (cotA+cotB+cotC)=1+secA secB secC`.

If A+B+C=pi , prove that : (cotB+cotC) (cotC+cotA) (cotA+cotB)=cosecA cosecB cosecC

If A+B+C=pi , prove that: cotB cotC + cotC cotA + cotA cotB=1 .

In a DeltaABC , prove that : tanA+tanB+tanC= tanA tanB tanC

In a DeltaABC , prove that : tanA+tanB+tanC= tanA tanB tanC

If A-B=pi/4 , then prove that: (1+tanA)(1-tanB)=2

If A+B+C= pi/2 , show that : tanA tanB + tanB tanC + tanC tanA=1

Prove that (cotA+tanB)/(cotB+tanA)=cotAtanB

If A+B+C=pi/2 , show that : cotA+cotB+cotC=cotA cotB cotC

Prove that : (tanA)/(1-cotA)+(cotA)/(1-tanA)=1+secA" cosec"A

If A, B, C, D be the angles of a quadrilateral, prove that : (tanA+tanB+tanC+tanD)/(cotA+cotB+cotC+cotD) = tan A tan B tan C tan D