SOLUTION: find all zeroes f(x)=25x^8-234x^4+81

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Question 1091093: find all zeroes
f(x)=25x^8-234x^4+81
Answer by CubeyThePenguin(3113) About Me  (Show Source):
You can put this solution on YOUR website!
Let y = x^4

f(x) = 25y^2 - 234y + 81
= (25y - 9)(y - 9)

x^4 = 9 ---> x = sqrt(3), -sqrt(3), i+%2A+sqrt%283%29, -i+%2A+sqrt%283%29
x^4 = 9/25 ---> x = 3sqrt(5)/5, -3sqrt(5)/5, 3i+%2A+sqrt%285%29%2F5, -3i+%2A+sqrt%285%29%2F5