Problems

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The circles σ1 and σ2 intersect at points A and B. At the point A to σ1 and σ2, respectively, the tangents l1 and l2 are drawn. The points T1 and T2 are chosen respectively on the circles σ1 and σ2 so that the angular measures of the arcs T1A and AT2 are equal (the arc value of the circle is considered in the clockwise direction). The tangent t1 at the point T1 to the circle σ1 intersects l2 at the point M1. Similarly, the tangent t2 at the point T2 to the circle σ2 intersects l1 at the point M2. Prove that the midpoints of the segments M1M2 are on the same line, independent of the positions of the points T1,T2.

Find the minimum for all α, β of the maximum of the function y(x)=|cosx+αcos2x+βcos3x|.