Above is a piecewise function which means part of the graph is linear (5x) and part of the graph is a parabola (x^2 + 4)>
A closed circle means it includes the value so a closed circle would be used for the top expression of 5x and an open circle would be used for x^2 + 4.
As x=3 is included in the top equation which is a closed circle when x = 3 and y = 15 (when we substitute x = 3 into 5x)
With x >3, it is an open circle at x =3…when we substitute x = 3 into x^2 + 4 we get 13.
This relative frequency asks how many of the males prefer skiing.
How many males?
How many of them prefer skiing?
Create a fraction of these two numbers: (The number who prefer skiing)/(#of males)
Whenever there is a y-intercept, x = 0
For f(x), where is the y-intercept? Look at the y-axis — where does it cross?
For g(x), substitute in x = 0, so g(0) = 3^0 + 2
For h(x), look at the table for when x = 0.
Then compare these y-intercepts with one another.
Which is the greatest?
Use the TI-83/4 for this one.
Below is y = x^2 This graph shows y = (x – 2)^2 +3
How many spaces did it shift horizontally?
How many spaces did it shift vertically?
4x^2 – 25 is the difference of two squares as 4x^2 is a perfect square as (2x)^2 and 25 is a perfect square as 5^2.
You can find the answer by:
FOILing each of the four choices
or
Putting 4x^2 – 25 into Y1 and putting each of the others into Y2 and then either graphing to see they are the same or checking the table to see they are the same
or
Can pick a number for x like 10 and putting 10 in for x into the original expression and then into each of the choices
Math Confidence by Robin the Math Lady 