`(4)/(3)cot^(2)30^(@)+3 sin^(2) 60^(@)-2 "cosec"^(2)60^(@)-(3)/(4) tan^(2)30^(@)`
`=(4)/(3) xx (sqrt(3))^(2)+3xx((sqrt(3))/(2))^(2)-2xx((2)/(sqrt(3)))^(2)-(3)/(4)xx((1)/(sqrt(3)))^(2)`
`=(4)/(3) xx 3+3xx(3)/(4)-2xx(4)/(3) -(3)/(4)xx(1)/(3)=4+(9)/(4)-(8)/(3)-(1)/(4)`
`=(48+27-32-3)/(12)=(75-35)/(12)=(40)/(12)=(10)/(3)=3(1)/(3)` .
