In one U.S. city, the quadratic function models the median, or average, age, y, at which men were first married x years after 1900. In which year was this average age at a minimum? (Round to the nearest year.) What was the average age at first marriage for that year? (Round to the nearest tenth.)

Answer 1

y= ax^2+bx+ c

using calculus...

dy/dx=2ax+b=0
x=-b/2a is either the max, or min.

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