Can anyone help me with both problems please?
1 answer:
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Answer:
-3 1/3
Step-by-step explanation:
The quadratic
... y = ax² +bx +c
has its extreme value at
... x = -b/(2a)
Since a = 3 is positive, we know the parabola opens upward and the extreme value is a minimum. (We also know that from the problem statement asking us to find the minimum value.) The value of x at the minimum is -(-4)/(2·3) = 2/3.
To find the minimum value, we need to evaluate the function for x=2/3.
The most straightforward way to do this is to substitue 2/3 for x.
... y = 3(2/3)² -4(2/3) -2 = 3(4/9) -8/3 -2
... y = (4 -8 -6)/3 = -10/3
... y = -3 1/3
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<em>Confirmation</em>
You can also use a graphing calculator to show you the minimum.
Answer:
- yes
- no
Step-by-step explanation:
When a number of similar calculations are required, a spreadsheet can reduce the tedium.
1. The price is a constant $1.88 per pound, so is proportional to the weight.
_____
2. The price is not proportional to the number of toppings.
__
The cost of the pizza is $8.99 plus $1.50 per topping. The base cost being non-zero ensures that the overall cost is not proportional to the number of toppings.
