A(x) = 3x - 12
b(x) = x - 9
a(b(x)) = a(x - 9) = 3(x - 9) - 12 = 3x - 27 - 12 = 3x - 39
a(b(x)) = 3x - 39
Answer:
217.04 cm²
Step-by-step explanation:
We should first calculate the area of the rectangle:
A= 14*21 =294cm²
then we should substract the area of the half-cercle :
A'= (7²*π)/2=76.96 cm²
then the area of the shaded area is :
A"= 294-76.96= 217.04 cm²
Answer:
28
Step-by-step explanation: radius is half the diameter
Answer and Step-by-step explanation:
Variance is the measurement of the spread bewteen the numbers of the data set and can be calculated by the formula:
σ² = ∑(x - ⁻x)² / n
1) With the data, find its mean (⁻x) by adding all the values and dividing the sum by total number of elements the data has;
2) Subtract each value of the data to the mean;
3) Square the result of the subtractions;
4) Add the squares;
5) Divide the sum by the total number of elements of the set;
6) The result is the Variance (σ²);
Standard Deviation is the measure of how far the values of the data set are from the mean and it is the square root of Variance:
σ = 
So, to calculate standard deviation, you just take the square root of the variance.