Let α=∑ₖ₌₁^∞ sin ^(2 k)(π/6). Let g:[0,1] → R be the function defined by g(x)=2^(α x)+2^(α(1-x)). Then, which of the following statements is/are TRUE ?
α=∑k=1∞sin2k(6π)g(x)=2αx+2α(1−x),x∈[0,1]Check: the min and max of g on [0,1],and whether each is attained at more than one pointsin6π=21α=∑k=1∞(41)k=1−1/41/4=31g(x)=2x/3+2(1−x)/3,x∈[0,1]2x/3⋅2(1−x)/3=21/3(constant)g(x)≥221/3=27/6x/3=(1−x)/3⇒x=21gmin=27/6 at the single point x=21u=2x/3∈[1,21/3],g=u+u21/3g is convex in u⇒the max is at an endpointg(0)=1+21/3=g(1)gmax=1+21/3 at x=0 and x=1(1)✓(2)✓(3)✓(4)×Answer: (1), (2), (3)