SOLUTION: Find all values of x for which f(x)=o when f is defined by f(x)=x^2-4x-1.

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Question 881375: Find all values of x for which f(x)=o when f is defined by f(x)=x^2-4x-1.
Answer by josgarithmetic(39618) About Me  (Show Source):
You can put this solution on YOUR website!
What? o or 0 ?
If you mean this, x%5E2-4x-1=0 then you can use general solution to a quadratic formula:
x=%284%2B-+sqrt%28%28-4%29%5E2-4%2A1%2A%28-1%29%29%29%2F2
x=%284%2B-+sqrt%2820%29%29%2F2
x=%284%2B-+2sqrt%285%29%29%2F2
highlight%28x=2%2B-+sqrt%285%29%29%29

If you did mean o=x%5E2-4x-1, this can be dealt similarly after adding -o to both sides.