- #1
Chas3down
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Homework Statement
Determine A and B so that y = Ax^(1/9) + Bx(-1/9) has an inflection point as (1/9)
Homework Equations
A + B = 9
The Attempt at a Solution
F' = Ax^(-8/9)/9 - Bx^(-10/9)/9
F'' = -8Ax^(---)/81 + 10Bx^(---)/81
-8A + 10B = 0
A + B = 9
-10(9-A) - 8A = 0
-90 - 18A = 0
A = -90/18
B = 14
But, this is not correct.. I don't understand what I did wrong?