2017 graphs and Tables exam
question 1
from the graphics calculator
transfered to the graph on the exam script
For the first 5 days the new deal costs more, but from day 6 to day 13 it is cheaper. From day 14 the original or normal price is cheaper.
question 2
from the graphics calculator
or using the calculator
From the menu select EQUATION (EQUA) for short. Select POLYNOMIAL (F2) and 2 degree becasue its a square function.
Enter in the values that correspond to a, b and c from the quadratic equation. That is:
a = 1/3 b = -2 c = 2.8
a = 1/3 b = -2 c = 2.8
The solutions are x = 3.775 m and x = 2.225 m and the difference is 1.55 m. So the holes are 1.55 m apart
question 3
Or using the graphic calculator in STATS mode. List the known x values and their corresponding y values into list 1 and 2 respectively. Click on GRPH, select GPH1. Click CALC and X^2 (parabola). Using ax^2 +bx+c, since a = 1, b =-4 and c =-12, we get y = x^2 - 4x - 12. Note that this is the same as y = (x + 2)(x - 6) and (x - 2)^2 - 16 but in expanded form.
When you see the word investigate you should think 'draw diagrams and tables!