Math question: In a circle, if an angle at the circumference is twice the size of an angle at the center, what is the measure of the angle at the center?
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What is the value of acos(sqrt(2)/2) + atan(1) ?
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Math Question: Use the distributive property to factorize 5x(2y + 3z) - 4x(y - 2z). Simplify.