Answer:
Explanation:
Given function: f(x) = -2x² - 3x + 20
To find the x-intercepts of a function, f(x) = 0
=================
-2x² - 3x + 20 = f(x)
-2x² - 3x + 20 = 0
-2x² - 8x + 5x + 20 = 0
-2x(x + 4) + 5(x + 4) = 0
(-2x + 5) (x + 4) = 0
-2x + 5 = 0, x + 4 = 0
-2x = -5, x = -4
x = -5/-2,x = -4
x = 5/2, x= -4
Coordinates: (-4, 0), (5/2, 0)
Answer:
1.60
Step-by-step explanation:
Assuming that this is a cylindrical pipe, the area can be determined by applying the formula for calculating the area of a circle.
i.e Area =
So that,
for the inner part of the pipe,
r =
=
= 2.5 feet
Area of the inner part of the pipe =
= 3.14 x
= 19.625
Are of the inner part of the pipe is 19.63 .
Total diameter of the pipe = 5 + 0.2
= 5.2 feet
r =
= 2.6 feet
Area of the pipe =
= 3.14 x
= 21.2264
Area of the pipe is 21.23 .
Thus the cross sectional area = Area of the pipe - Area of the inner part of the pipe
= 21.2264 - 19.625
= 1.6014
The cross sectional area of the cement pipe is 1.60 .