Answer:
4π
Step-by-step explanation:
We are asked to calculate the area of a circle whose diameter is equal to 4, we know that the area of the circle is given by the following equation:
A = π * (r ^ 2)
where r is the radius of the circle, we know that the radius of the circle is half the diameter, therefore:
r = d / 2 = 4/2
r = 2
replacing, we are left with:
A = π * (2 ^ 2)
A = 4π
Which means that the area of the circle is 4π
After plotting the quadrilateral in a Cartesian plane, you can see that it is not a particular quadrilateral. Hence, you need to divide it into two triangles. Let's take ABC and ADC.
The area of a triangle with vertices known is given by the matrix
M =
![\left[\begin{array}{ccc} x_{1}&y_{1}&1\\x_{2}&y_{2}&1\\x_{3}&y_{3}&1\end{array}\right]](https://tex.z-dn.net/?f=%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D%20x_%7B1%7D%26y_%7B1%7D%261%5C%5Cx_%7B2%7D%26y_%7B2%7D%261%5C%5Cx_%7B3%7D%26y_%7B3%7D%261%5Cend%7Barray%7D%5Cright%5D%20)
Area = 1/2· | det(M) |
= 1/2· | x₁·y₂ - x₂·y₁ + x₂·y₃ - x₃·y₂ + x₃·y₁ - x₁·y₃ |
= 1/2· | x₁·(y₂ - y₃) + x₂·(y₃ - y₁) + x₃·(y₁ - y₂) |
Therefore, the area of ABC will be:
A(ABC) = 1/2· | (-5)·(-5 - (-6)) + (-4)·(-6 - 7) + (-1)·(7 - (-5)) |
= 1/2· | -5·(1) - 4·(-13) - 1·(12) |
= 1/2 | 35 |
= 35/2
Similarly, the area of ADC will be:
A(ABC) = 1/2· | (-5)·(5 - (-6)) + (4)·(-6 - 7) + (-1)·(7 - 5) |
= 1/2· | -5·(11) + 4·(-13) - 1·(2) |
= 1/2 | -109 |
<span> = 109/2</span>
The total area of the quadrilateral will be the sum of the areas of the two triangles:
A(ABCD) = A(ABC) + A(ADC)
= 35/2 + 109/2
= 72
Answer:
B. 0.4
Step-by-step explanation:
5 + 4 + 3 = 12 balls
5 blue / 12 balls = 0.4
Initial, x = 0, b = 50000
day 1, x = 1, b = 50000 (1.05)^-1
day 2, x = 2, b = 50000 (1.05) =^-2
day 2 / day 1 = 1.05^-2 / 1.05^-1 = 1.05^-1 = 0.952
Which means that the number of bacteria decreased 4.8%
7 4-credit classes. 4 3-credit classes.
7*4 = 28, and 4*3 = 12. 11 classes, and 40 credits.