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Evaluate: `cos(sin^(-1)1/4+sec^(-1)4/3)`A. `(3sqrt(15)-sqrt(7))/(16)`B. `(3sqrt(15)+sqrt(7))/(16)`C. `(sqrt(7)-3sqrt(15))/(16)`D. `(3sqrt(15)-sqrt(7))/(4)`

Answer» `cos(sin^(-1)1/4+sec^(-1)4/3)`
`=cos(sin^(-1)1/4+cos^(-1)3/4)`
`cos(sin^(-1)1/4)cos(cos^(-1)3/4)-sin^(-1)1/4)sin(cos^(-1)3/4)`
`=cos(cos^(-1))sqrt(15)/(4)cos(cos^(-1)3/4)-sin(sin^(-1)1/4)sin(sin^(-1)sqrt(7)/(4))`
`=sqrt(15)/(4)xx3/4-1/4xxsqrt(7)/(4)=3sqrt(15)-sqrt(7)/(16)`


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