Answer:
vertex = (- 1, - 4 )
Step-by-step explanation:
Given a parabola in standard form
y = ax² + bx + c ( a ≠ 0 )
Then the x- coordinate of the vertex is
x = -
y = x² + 2x - 3 ← is in standard form
with a = 1, b = 2 , then
x = - = - 1
Substitute x = - 1 into the equation for corresponding value of y
y = (- 1)² + 2(- 1) - 3 = 1 - 2 - 3 = - 4
vertex = (- 1, - 4 )
Answer: option d.
Step-by-step explanation:
You have the following formul given in the problem:
You know that:
The number of customers serviced in an hour by the technical support representative is 6 costumbers, therefore:
As the problem asked for the probability that a costumber will be on hold less than 30 minutes, we know that:
Substitute the values above into the formula.
Then, you obtain:
or 95%