Obtian all other zeroes of `(x^(4)+4x^(3)-2x^(2)-20x-15)` if two of its zeroes are ` :' sqrt(5)` and `-sqrt(5)` .

Explanation

To find all the zeros of the polynomial \( f(x) = x^4 + 4x^3 - 2x^2 - 20x - 15 \), given that two of its zeros are \( \sqrt{5} \) and \( -\sqrt{5} \), we can follow these steps:

### Step 1: Identify the known zeros and their corresponding factors
Since \( \sqrt{5} \) and \( -\sqrt{5} \) are zeros of the polynomial, we can form a quadratic factor from these roots:
\[ (x - \sqrt{5})(x + \sqrt{5}) = x^2 - 5 \]

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