Analyzing lines and fit
9. Error Analysis Describe and correct the error a student made in determining the equation for the line of best fit for the data in the table.
x: 3 6 9 12 15 18 21 y: 4 17 28 40 55 67 72
Enter y data in L1 and x data in L2. Then perform a linear regression. Line of best fit: y = 0.25x + 1.83 ✗
Enter the x data in for L1 and enter the y data for L2 . Then perform the linear regression. The correct line fit is y=3.94x - 6.86
Identify the x- and y-intercepts of the graph of each equation.
15. 2x + 5y = 10 16. 3x − 4y = −24
15. x=(5,0) y=(0,2)
16.x=(8,0) y=(0,-6)
Write each exponential function.
21. x: 0 1 2 3 4 y: 2 8 32 128 512
22. 2. x: 0 1 2 3 4 y: 4 4/3 4/9 4/27 4/81
21. y= 2 x (4)x
22. y= 4 x (1/3)x
Find the solution to the equation x2 + 4x = −12.
-2 + or - 2 sqrt2
Find the value of f(5) for each function.
13. f(x) = 6 + 3x 14. f(x) = −2(x + 1)
13.x=21 14. -12
Use technology to perform a linear regression to determine the equation for the line of best fit for the data. Estimate the value of y when x = 19.
14. x:2 14 16 18 20 15. 16 20 24 28 32
y:35 39 41 44 48 y: 105 83 62 34 15
14. y= 0.63x+32.58 15. y=-5.725x+197.2
x=44.55 x= 88.425
Write each equation in standard form.
33. y = 4x − 18 34. y = 2x +3/7
33. 4x-y=18 34. 14x-7x=-3
Given the exponential function:
f(x) = 3(2)x + 6. Find the y-intercept, range , and domain.
y=(0,9)
x= all real numbers
y= y>6
50. SAT/ACT The expressions f(x) = x2 + 12x + c and g(x) = x2 − 20x + d are perfect-square trinomials. What is the value of f(0) − g(0)?
0
Find the value of f(14) for each function.
17. f(m) = 1 − 4(m/2 ) 18. f(m) = 2(m − 3)
17. m=-27 18. m=22