For which values of b will the equation x^2+bx+1=0 have real solutions?

👨🏻‍🏫 學術台數學

[匿名]

2015-09-01 3:12 am

回答 (3)

[匿名]

2015-09-01 5:00 am

The discriminant (b^2 - 4ac) will need to be zero or positive:

b^2 - 4(1)(1) ≥ 0
b^2 ≥ 4
|b| ≥ 2

b ≥ 2

-b ≥ 2
b ≤ -2

b ≥ 2 OR b ≤ -2

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用戶48836

2015-09-01 3:35 am

The discriminant from the quadratic formula in this case is b^2-4. What happens when it is negative?
What are the appropriate values of b?

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[匿名]

2015-09-01 3:13 am

Use the quadratic formula to answer the question.

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