If `(1+sinA)(1+sinB)(1+sinC)=(1-sin-A)`
`(1-sinB)(1-sinC)," then prove that "(1+sinA)`
`(1-sinB)(1-sinC)=pmcosA.cosB.cosC`.

Explanation

Multiplying both sides by `(1-sinA)(1-sinB)(1-sinC)`, we get
`(1-sin^2A)(1-sin^2B)(1-sin^2C)`
`= (1-sinA)^2(1-sinB)^2(1-sinC)^2`
`rArr (1-sinA)(1-sinB)(1-sinC)`
`=pmcosAcosBcosC`
Similrly,`(1+sinA)(1+sinB)(1+sinC)`
`=pmcoAcosBcosC`