The answererrrrrr isssssss 15
A parabola is a quadratic function, and a quadratic can be expressed in vertex form, which is:
y=a(x-h)^2+k, where (h,k) is the vertex (absolute maximum or minimum point of the quadratic)
In this case we are given that (h,k) is (-5,80) so we have so far:
y=a(x--5)^2+80
y=a(x+5)^2+80, we are also told that it passes through the point (0,-45) so:
-45=a(0+5)^2+80
-45=25a+80 subtract 80 from both sides
-125=25a divide both sides by 25
-5=a, so now we know the complete vertex form is:
y=-5(x+5)^2+80
The x-intercepts occur when y=0 so:
0=-5(x+5)^2+80 add 5(x+5)^2 to both sides
5(x+5)^2=80 divide both sides by 5
(x+5)^2=16 take the square root of both sides
x+5=±√16 which is
x+5=±4 subtract 5 from both sides
x=-5±4 so the x-intercepts are:
x=-1 and -9
Answer:
The answer is B
Step-by-step explanation:
Answer:
1) There are 13 students in Jerry's study.
2) There are 39 students in Kathy's study.
3) Jerry's study is more trustworthy!
Step-by-step explanation:
1) Jerry's study is the one with the dot plot.
Now, the number of students is calculated by adding the total number of dots in the plot.
We have a total of 13 dots.
Thus, there are 13 students in Jerry's study.
2) Kathy's study is the one with the histogram.
The total number of students is gotten by adding the corresponding number of students on the y-axis for each range of distance on the x-axis.
Total number of students = 9 + 11 + 7 + 12 = 39 students
3) Jerry's study where he used a dot plot is likely to be more trustworthy because it gives exact values of the number of students for each distance represented whereas, Kathy's study where she used a histogram doesn't give exact values but just gives a range of distances for a particular number of people.
