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Question
Write the value of `tan(2tan^(-1)(1/5))`
Solution
`2tan^(-1)x=tan^(-1)(2x)/(1-x^2)`
`therefore 2 tan^(-1)(1/5)=tan^(-1)((2(1/5))/(1-(1/5)^2))=tan^(-1)(5/12)`
Thus `tan (2tan^(-1)(1/5))=tan(tan^(-1)(5/12))=5/12`
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