Question

State the rule obeyed by the variables in each relation diagram below

Answer 1

Answer:

y = 2x + 1

Step-by-step explanation:

You can see a pattern in the group of x's that the numbers go up by 1 Also in the y-set that the numbers go up by 2. So this pattern is linear, that means the "rule" you are looking for does not have exponents or square roots or any very complicated stuff. You can use a guess and check method. Say to yourself how can I get a 7 out, when I put a 3 in? "times by2 and plus 1" works.

3 times 2, and plus1

gives you 7.

Test it on the other numbers.

-1 times2, and plus1

2(-1)+1 = -1

2(0)+1 = 1

2(1)+1 = 3

2(2)+1 = 5

It works for all the numbers.

You can calculate it also, using any two pairs of (x,y) from the data set. Put y-y on top of a fraction and x-x on the bottom. You will get the slope and that is the 2 in the "rule"

(3,7) and (2,5) for example. 7-5 so put 2 on top and 3-2 so put 1 on the bottom. 2/1 is just 2. From the point (0,1) we know the y-intercept is 1. This also gives the equation y=2x+1.

If you are just starting to learn this, probably just guess and check a rule. The rule has to work for all the points.