Answer:
Question 13 of 16 Evaluate the following function at the values 2, -4, and x-1. f(x)=x2-5 = ..... f(2)= (Type an integer or a simplified fraction.) f(-4)=L(Type an integer or a simplified fraction.) f(x-1)= (Simplify your answer. Type an expression using x as the variable. Use integers or fractions for any numbers in the expression.)
Answer:
This shows 3 pivot position matrixes.
Step-by-step explanation:
The given matrix is:
![\left[\begin{array}{ccc}1&-2&-5\\0&4&3\\-3&3&0\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%26-2%26-5%5C%5C0%264%263%5C%5C-3%263%260%5Cend%7Barray%7D%5Cright%5D)
The option D is correct for this matrix.
The matrix is invertible and the given matrix has 3 pivot positions.
The matrix is invertible if its determinant is nonzero.
Multiply the 3rd row by 1/3.we get:
![\left[\begin{array}{ccc}1&-2&-5\\0&4&3\\-1&1&0\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%26-2%26-5%5C%5C0%264%263%5C%5C-1%261%260%5Cend%7Barray%7D%5Cright%5D)
Now, add the first row with third row:
![\left[\begin{array}{ccc}0&-1&-5\\0&4&3\\-1&1&0\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D0%26-1%26-5%5C%5C0%264%263%5C%5C-1%261%260%5Cend%7Barray%7D%5Cright%5D)
Replace third row by first row:
![\left[\begin{array}{ccc}-1&1&0\\0&4&3\\0&-1&-5\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-1%261%260%5C%5C0%264%263%5C%5C0%26-1%26-5%5Cend%7Barray%7D%5Cright%5D)
This shows 3 pivot position matrixes.
Hence, a matrix is invertible and has 3 pivot positions.
Answer: d) 255 ≤ f(x) ≤ 340
Step-by-step explanation:
The function
f(x)= 8.5x
represents the amount of money that Steve earns given the number of hours, x, he works.
The dependent variable is the total amount that he earns, f(x) while the independent variable is the number if hours, x that he works. The range is the possible values of the dependent variable that satisfies the equation.
Steve works between 30 and 40 hours per week. This means that
the lowest amount that he earns is 8.5×30 = $255
The highest amount that he earns is 8.5× 40 = 340. Therefore, the range is
255 ≤ f(x) ≤ 340
