Answer:
Step-by-step explanation:
The standard form of a parabola is
If we know the y intercept is (0, 400), that means that when x = 0, y = 400. That allows us to begin by finding c:
and c = 400.
Now to find a and b. Using the fact that the vertex is (1, 405), we know that h is 1 and k is 405. If
and h = 1, then
and
2a = -b so
b = -2a. Save that for a minute or two.
If
and k = 405, then
and
and
405 = 400 - 4a and
5 = -4a so
We will use that a value now to find the value of b. If b = -2a, then
and
Writing our parabolic equation now:
Finding the x-intercepts is just another way of saying "factor this quadratic" so we will begin that by setting the quadratic equal to 0:
and who hates all those fractions more than I do? Probably nobody, so we are going to get rid of them by multiplying everything by 4 to get
Assuming you can throw that into the quadratic formula to solve for the 2 values of x where y = 0, you'll find that the x-intercepts are
x = -16.91647287 and 18.91647287
Part A
The number of members in the equal-size groups will be the Greatest Common Divisor of the numbers 20 and 25. That number is 5. There are several ways to find this number. One way is to look at the prime factors of 20 and 25:
20 = 2*2*5
25 = 5*5
The largest factor common to both is 5.
There will be 5 students in each group.
Part B
The number of groups is the number of students divided by the size of the group.
There will be 20/5 = 4 groups of sixth graders.
There will be 25/5 = 5 groups of seventh graders.
I’m pretty sure it should be ,B
Answer:
A.20 ft
Step-by-step explanation:
the shadow is double the height of the object.