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if cosA+sinA=secA+cosecA=n, prove that n(m*m-1)=2m.

n(m*m-1)=(secA+cosecA)*((cosA+sinA)*(cosA+sinA)-1)

= (secA+cosecA)*((cos^2A+sinAcosA+sinAcosA+sin^2A)-1)
= (secA+cosecA)*((1+2sinAcosA)-1)

= ((secA+cosecA)*(1+2sinAcosA-1))

=(secA+cosecA)*(2sinAcosA)

=2secAsinAcosA + 2cosecAsinAcosA

=2sinA+2CosA

=2m


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