1.

The value of `sqrt(3) cot 20^(@) -4cos20^(@)` isA. `1`B. `-1`C. `0`D. non of these

Answer» Correct Answer - A
`sqrt(3)cot 20^(@)-4cos 20^(@)`
`=(sqrt(3)cos20^(@))/(sin20^(@))-4cos 20^(@)`
`=(sqrt(3)cos 20^(@)-4sin20^(@)cos20^(@))/(sin20^(@))`
`=(2[sqrt(3)/(2)cos 20^(@)-2sin20^(@)cos20^(@)])/(sin20^(@))`
`=(2(sin60^(@)cos20^(@)-sin40^(@)))/(sin20^(@))`
`=([2sin60^(@)cos20^(@)-2sin40^(@)])/(sin20^(@))`
` =(sin80^(@)+sin40^(@)-2sin40^(@))/(sin20^(@))`
`=(sin80^(@)-sin40^(@))/(sin20^(@))`
`=(2cos60^(@).sin20^(@))/(sin20^(@))`
`2xos60^(@)=1`


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