If the equation `cot^4x-2cos e c^2x+a^2=0` has at least one solution, then the sum of all possible integral values of `a` is equal to

Explanation

`cot^4x-2cosec^2x+a^2 = 0`

`=>cot^4x-2(1+cot^2x)+a^2 = 0`

`=>cot^4x-2cot^2x+a^2-2 = 0`

`=>cot^4x-2cot^2x+1+a^2-3 = 0`

`=>(cot^2x-1)^2 +(a^2-3) = 0`

`=>(cot^2x-1)^2 = 3-a^2`

As, there is at least one solution for this equation,

`:. 3-a^2 ge 0`

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