1.

Prove that: `sin^-1(3/5)-cos^-1(12/13)=sin^-1(16/65)`

Answer» LHS
`sin^(-1)(3/5)-cos^(-1)(12/13)`
Let`cos^(-1)(12/13)=theta`
`costheta=12/13`
`sintheta=5/13`
`theta=sin^(-1)(5/13)`
`sin^(-1)(3/5)-theta`
`sin^(-1)(3/5)-sin^(-1)(5/13)`
`sin^(-1)x-sin^(-1)y`
`(xsqrt(1-y^2)-ysqrt(1-x^2))`
`sin^(-1)(3/5*sqrt(1-(5/13)^2)-5/13sqrt(1-(3/5)^2)`
`sin^(-1)(3/5*12/13-5/13*4/5)`
`sin^(-1)(36/65-20/65)`
`sin^(-1)(16/65)=RHS`.


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