Answer:
Parabola
Step-by-step explanation:
We are given that a function

The given function is an equation of parabola along y- axis.
General equation of parabola along y- axis with vertex (h,k) is given by


Compare it with given equation then we get
h=5, k=3
Vertex of given parabola =(5,3)
Substitute x=0 then we get

y-intercept of parabola is at (0,28).
Answer:
B. 95% confident the average concentration of PCBs in the water supply is between 2.9 ppb and 3.5 ppb
Step-by-step explanation:
You are given the total number of samples, the concentration of lead, and the standard deviation. The standard deviation represents how inaccurate the estimation of the concentration of lead in the drinking water. This means that there can only possibly be a 0.3 ppb error in the estimation. 3.2-0.3=2.9, and 3.2+0.3=3.5
Yes. I think so. Even if there is not intercept the intercept is 0
Given:
The power generated by an electrical circuit (in watts) as function of its current x (in amperes) is modeled by:

To find:
The current that will produce the maximum power.
Solution:
We have,

Here, leading coefficient is negative. So, it is a downward parabola.
Vertex of a downward parabola is the point of maxima.
If a parabola is
, then

In the given function, a=-12 and b=120. So,



Putting x=5 in the given function, we get




Therefore, 5 watt current will produce the maximum power of 300 amperes.
Try this solution:
let the unknown two-digits number be 'xy'.
Then it is possible to write any two-digit number as 10x+y, where x - the tens digit and y - the unit digit.
Using the rule described above the phrase 'the tens digit of a number is twice the units digit' may be written as x=2y.
Using the same rule the phrase 'if the digits are reversed, the new number is 36 is less than the original number' may be written as (10x+y)-(10y+x)=36.
These two equations may be resolved as system of two equations:

Check: the original number is 84, the new number is 48; difference is 84-48=36.
answer: 84