Prove that: Sin (3pi-A)×cos (A-pi/2)×tan (3pi/2-A) by cosec (3pi/2+A)×sec (3pi+A)×cot (A-pi/2)=cos^4A. Share with your friends Share 2 Ashwini Kumar answered this We have,sin3π-AcosA-π2tan3π2-Acosec3π2+Asec3π+AcotA-π2=sinA sinA cotA-secA-secA-tanA=-sinA sinA cosAsinA1cosA×1cosA×sinAcosA=-cos4A 4 View Full Answer