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

To solve the equation \( \cot^4 x - 2 \cos^2 x + a^2 = 0 \) and find the sum of all possible integral values of \( a \) such that the equation has at least one solution, we can follow these steps:

### Step 1: Rewrite the equation
The original equation is:
\[ \cot^4 x - 2 \cos^2 x + a^2 = 0 \]
We can express \( \cos^2 x \) in terms of \( \cot^2 x \):
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