` cot [ ( pi ) /(2) - 2 cot ^( -1) sqrt 3 ] `

Explanation

` cot [ ( pi ) /(2) - 2 cot ^( -1) sqrt 3 ] `
` = cot [ ( pi ) /(2 ) - 2 . (pi ) /(6) ], " " ( because cot ^( -1) sqrt3 = ( pi ) /(6) ) `
` = cot [ (pi ) /(2) - (pi ) /(3) ] = cot [ (pi ) /(6) ] `
` = sqrt 3, " " ( because cot "" (pi ) /(6) = sqrt 3 ) `