Which comes first in the alphabet, x or y? d or r?
Domain means the x values and Range means the y values
So we’re gonna graph this and check out the y values:
Looking at the graph, the lowest y value is less than -1. which can also be seen in the table above.
This gets rid of answers (3) and (4).
Are the y values greater or less than -9?
That’s it, 2 points.
Inspired by this tweet:
Looking at our latest Algebra I Regents, here in NY, here is a great example of the use of a graphing calculator and compare/contrast/use metacognition:
All 4 answer choices have a 3 but in different and important places!!
First question, does this xy table look like it is for a linear function?
We can look at the equations and see which f(x) = mx + b
We can also use the TI-84 and check the table to see if it matches the table above!
Let’s go to the graphing calculator:
Answer choice (1) below: this is linear and is clearly not a match especially since the rate of change is always 3 (every time x goes up by 1 y goes up by 3)
Answer choice (2) below is also linear as it has a constant rate of change…not a match:
Answer choice (3) is shown below and, well, we’re still lookin’:
2 points!!
These answers choices can be used to compare/contrast similarities and differences in their parent functions (linear, cubic and exponential).
First distribute the 5
3x + 2 ≤ 5x – 20 subtract 3x from both sides: 2 is on the left side and the right side is 2x -20
2 ≤ 2x – 20 now add 20 to both sides
22 ≤ 2x divide both sides by 2
11 ≤ x now match with the answer
Certainly answer (2) 750 minutes is a LOT longer than 12.5 seconds.
Answer (4) is more than half an hour (.5 hours)
Since 12.5 seconds is less than a minute we can find our answer from the remaining two answers pretty easily:
PS Dan is pretty fast!! https://www.quora.com/Whats-a-good-100m-sprint-time
Which of these numbers are in between 7.0 and 7.8?
It could have been more complicated than that but if we try the other answers, for example, 8.8 and add that to 7.2 and 7.6 and then divide by 3, the result will not be between 7.2 and 7.6.
Students have 3 hours so they can prove that the other anseers also do not work and find their answer. 2 points!!
Math Confidence by Robin the Math Lady 