Find the roots of the quadratic function by completing the square: x^2 + 4x - 1 = 0
2 answers:
Answer:
x = - 2 ±
Step-by-step explanation:
Given
x² + 4x - 1 = 0 ( add 1 to both sides )
x² + 4x = 1
To complete the square
add (half the coefficient of the x- term )² to both sides
x² + 2(2)x + 2² = 1 + 2² ← complete the square on the left side
(x + 2)² = 5 ← take the square root of both sides
x + 2 = ± ← subtract 2 from both sides
x = - 2 ±
roots are x = - 2 - or x = - 2 +
You might be interested in
Answer:
The degrees of freedom are given by:
And replaicing we got:
The 95% confidence interval would be between 26.9 and 31.1
Step-by-step explanation:
Information given
represent the sample mean
population mean
s represent the sample standard deviation
represent the margin of error
n represent the sample size
Solution
The confidence interval for the mean is given by the following formula:
(1)
And this formula is equivalent to:
And replaicing we got:
The 95% confidence interval would be between 26.9 and 31.1