M(x) = 4x^3 - 5x^2 - 7x
Let us first find the zeros of the function.
That is when it is equal to zero.
m(x) = 4x^3 - 5x^2 - 7x = 0
x(4x^2 - 5x - 7) = 0. Therefore x = 0 or 4x^2 - 5x - 7 = 0.
Using a quadratic function calculator to solve 4x^2 - 5x - 7
x = 2.09, -0.84
Therefore the zeros are x =-0.84, 0, 2.09 for the function m(x).
The intervals observed are imagining that the zeros are on the number line:
x<-0.84, -0.84<x<0, 0<x<2.09, x>2.09.
For each of this range we would test the function with a number that falls in the range.
The function is decreasing in the interval where it is less than 0.
For x<-0.84, let us test x = -1, m(x) = 4x^3 - 5x^2 - 7x = 4(-1)^3 - 5(-1)^2 - 7(-1) = -4 -5 +7 = -2, -2 < 0, so it is decreasing here.
For -0.84<x<0, let us test x = -0.5, m(x) = 4x^3 - 5x^2 - 7x = 4(-0.5)^3 - 5(-0.5)^2 - 7(-0.5) = -0.5 -1.25 +3.5 = 1.75, 1.75 >0. It is not decreasing.
For 0<x<2.09, let us test x = 1, m(x) = 4x^3 - 5x^2 - 7x =
4(1)^3 - 5(1)^2 - 7(1) = 4 -5 -7 = -8, -8 <0. It is decreasing.
For x>2.09, let us test x = 3, m(x) = 4x^3 - 5x^2 - 7x =
4(3)^3 - 5(3)^2 - 7(3) = 108 -45 -21 = 42, 42 >0. It is not decreasing.
So the function is decreasing in the intervals:
x < -0.84, & 0<x<2.09.
Answer:
r = 16 cm
g = 34 cm
LA = 1708.16 cm^2
Step-by-step explanation:
We have that for the cone, the formula is as follows:
v = pi / 3 * r ^ 2 * h
the first thing they ask is to calculate the radius, therefore we solve for r
r ^ 2 = 3 * v / (pi * h)
replacing the volume and height, it remains:
r ^ 2 = 3 * 2560 * pi / (pi * 30)
r ^ 2 = 3 * 2560/30 = 256
r = 16
Now, to calculate the slant height, that is to say g, we can calculate it knowing the height and the radius:
g ^ 2 = r ^ 2 + h ^ 2
g ^ 2 = 16 ^ 2 + 30 ^ 2
g ^ 2 = 1156
g = 34
The lateral area of the cone is given by the following equation:
LA = pi * r * g
replacing
LA = 3.14 * 16 * 34
LA = 1708.16 cm ^ 2
the lateral area is 1708.16 cm ^ 2
A quadratic equation is usually in the form:
where a, b and c are the coefficients of the expression and a ≠ 0.
If a = 0, the equation becomes a linear expression and is no longer quadratic.
Hence, in the above options; y = 5x -2 is the only one that is not a quadratic equation.
Answer:
First, you add 30 and 20, and you get 50. Then, since 30 is your highest priced item, you find 0.30 of 30, which is 9. After that you would subtract 9 from 30, which gives you 21. Therefore, we know the price is 41
Step-by-step explanation:
Answer: 1) 
2) 55 points
Step-by-step explanation:
1) A= 8w + 18, w=1.25
A = 8(1.25) + 18
A = 10 + 18
A = 28ft^2
2) 25 points to start with, additional 5 points per magazine they sell, m = number of magazines they sell
total points = 25 + 5m
How many if they sell 6?
total = 25 + 5(6)
= 25 + 30
total = 55
