4, because you can't have a negative square root.
Answer:
d
Step-by-step explanation:
Answer:
see explanation
Step-by-step explanation:
Check the value of the discriminant
Δ = b² - 4ac
• If b² - 4ac > 0 then roots are real
• If b² - 4ac = 0 roots are real and equal
• If b² - 4ac < 0 then roots are not real
given (x - a)(x - b) = k² ( expand factors )
x² - bx - ax - k² = 0 ( in standard form )
x² + x(- a - b) - k² = 0
with a = 1, b = (- a - b), c = -k²
b² - 4ac = (- a - b)² + 4k²
For a, b, k ∈ R then (- a - b)² ≥ 0 and 4k² ≥ 0
Hence roots of the equation are always real for a, b, k ∈ R
Answer:
see explanation
Step-by-step explanation:
Euler's formula for polyhedra is
V- E + F = 2
where V is number of vertices, E number of edges and F number of faces
Answer:
<em>The answer resides in the explanation.</em>
<em>Pls rate as brainliest </em>
Step-by-step explanation:
The predicted useful life of a brand A cutting tool when the speed is 45 meters per minute is 1.2 to 5.5 hours.
The predicted useful life of a brand B cutting tool when the speed is 45 meters per minute is 3.4 to 5.4 hours.
The prediction interval for brand A is larger than the prediction interval for brand B because the estimated standard error of y^ is different for the two intervals.
The prediction intervals are both larger than the corresponding confidence intervals.
The standard error for the estimated mean value of y is smaller than the standard error for the predicted value of y.
The predicted useful life of a brand A cutting tool that is operated at 100 meters per minute is -0.59 hours
The actual predicted useful life of a brand A cutting tool when the speed is 100 meters per minute is 0.0 to 2.3 hours.
