You can see from the table above that the y value is 0 when x = -5 and x = 5
It can also be seen from the graph above that the zeros
(where the function crosses the x-axis)
are at x = -5 and x = 5
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May 2016 Brain Teaser Solution
Answer: 98
3 x 2 + 1 = 7
5 x 4 + 3 = 23
7 x 6 + 5 = 47
9 x 8 + 7 = 79
10 x 9 + 8 = 98
Get the Math and Points Jan 2016 CC Alg I #25
Linear vs Exponential
Look at the pattern of t(x) which are the y values.
Every time x goes up by 2 (from -3 to -1, or -1 to 1, 1 to 3, or 3 to 5), t(x) goes down by 2.5.
This means that there is a constant rate of change or slope and that the function is linear.
These points can be plotted on graph paper to see if they will make a line which they do :)
Here is some more practice from the awesome site www.emathinstruction.com
https://emathinstruction.com/wp-content/uploads/2014/11/CCAlg1-U6L8-Linear-Versus-Exponential.pdf
Get the Stats and Get the Points CC Alg I Jan 2016 #24
Residuals show how far the data is from the line of best fit.
If a line is a good fit for the data, then the residuals will be about half below and half above the x axis. The residuals will also be close to the x-axis which means that their values are fairly small.
If the residual plot shows a pattern (see below), then a linear will not be a good fit. See the link from Math Bits below:
http://mathbitsnotebook.com/Algebra1/StatisticsReg/ST2Residuals.html
Looking at the 4 choices, which looks most like the the left most graph that says “Random, No Pattern. Linear Appropriate”?
Get the Math and the Points CC Alg I Jan 2016 #23
This question could be called Linear vs Exponential as it asks for linear with fancy wording: “equal difference over an equal interval”(as opposed to just the word linear)
(I) 3.5 cm a day would make the y values go up 3.5 each day this is linear
(II) depreciate 15% a year is exponential
(III) tripling is exponential
see #25 on this Regents for long answer of linear or exponential!!
Math Confidence by Robin the Math Lady 