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2021 SMT Guts Round 7 p25-28 - Stanford Math Tournament

Source:

February 11, 2022
algebrageometrycombinatoricsnumber theoryStanford Math TournamentSMT

Problem Statement

p25. Compute: i=0(2π)4i+1(4i+1)!i=0(2π)4i+1(4i+3)!\frac{ \sum^{\infty}_{i=0}\frac{(2\pi)^{4i+1}}{(4i+1)!}}{\sum^{\infty}_{i=0}\frac{(2\pi)^{4i+1}}{(4i+3)!}}
p26. Suppose points A,B,C,DA, B, C, D lie on a circle ω\omega with radius 44 such that ABCDABCD is a quadrilateral with AB=6AB = 6, AC=8AC = 8, AD=7AD = 7. Let EE and FF be points on ω\omega such that AEAE and AFAF are respectively the angle bisectors of BAC\angle BAC and DAC\angle DAC. Compute the area of quadrilateral AECFAECF.
p27. Let P(x)=x2ax+8P(x) = x^2 - ax + 8 with a a positive integer, and suppose that PP has two distinct real roots rr and ss. Points (r,0)(r, 0), (0,s)(0, s), and (t,t)(t, t) for some positive integer t are selected on the coordinate plane to form a triangle with an area of 20212021. Determine the minimum possible value of a+ta + t.
p28. A quartic p(x)p(x) has a double root at x=214x = -\frac{21}{4} , and p(x)1344xp(x) - 1344x has two double roots each 14\frac14 less than an integer. What are these two double roots?
PS. You should use hide for answers. Collected [url=https://artofproblemsolving.com/community/c5h2760506p24143309]here.