What is the <strong>MINIMUM</strong> value of \sin^4\theta+\cos^4\theta-2 \sin^2\theta \cos^2\theta?

Explanation

The given expression can be factored as a perfect square: (\sin^2\theta - \cos^2\theta)^2. Since the square of a real number is always non-negative, the minimum possible value is 0 (which occurs when \sin^2\theta = \cos^2\theta).

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