which data set represents an increasing linear function?

a) (1,-2),(3,1),(5,4),(7,7)
b) (1,1),(2,0),(3,-1),(4,-2)
c) (1,-3),(3,5),(5,11),(7,18)
d) (1,17),(2,15),(3,11),(4,3)

my answer: c) (1,-3),(3,5),(5,11),(7,18)

Answer a)

x1 = 1 , y1= - 2

x2 = 3 , y2 = 1

x3 = 5 , y3= 4

x4 = 7 , y4 = 7

x2 - x1 = 3 - 1 = 2

x3 - x2 = 5 - 3 = 2

x4 - x3 = 7 - 3 = 2

y2 - y1 = 1 - ( - 2 ) = 1 + 2 = 3

y3 - y2 = 4 - 1 = 3

y4 - y3 = 7 - 4 = 3

Numerically, y increases by 3 units for every 2 unit increase of x.

correct

http://www.wolframalpha.com/input/?i=plot+%281%2C-3%29%2C%283%2C5%29%2C%285%2C11%29%2C%287%2C18%29

Reiny

c)

isn't correct answer

In w o l f r a m a l p h a . c o m

type:

interpolate (1,-3),(3,5),(5,11),(7,18)

That is a cubic polynomial.

and

x4 - x3 = 7 - 5 = 2

sorry, did not register the "linear" part, and concentrated on the "increasing"

actually I think it is a),

the slope between any two points is 3/2

all points satisfy the equation
3x-2y=7

http://www.wolframalpha.com/input/?i=interpolate+%281%2C-2%29%2C%283%2C1%29%2C%285%2C4%29%2C%287%2C7%29+

Bosnian was right in his first post.

(think I will have a third cup of coffee to wake up)

To determine which data set represents an increasing linear function, we need to examine the relationship between the x-coordinates (input) and the y-coordinates (output).

An increasing linear function is one in which the y-coordinate increases as the x-coordinate increases.

Let's go through each option to check:

a) (1,-2),(3,1),(5,4),(7,7)
Here, as the x-coordinate increases from 1 to 3, the y-coordinate increases from -2 to 1. So far, it seems to be increasing. But when the x-coordinate increases from 3 to 5, the y-coordinate increases from 1 to 4, which is smaller than the previous increase. Hence, this data set does not represent an increasing linear function.

b) (1,1),(2,0),(3,-1),(4,-2)
In this set, as the x-coordinate increases, the y-coordinate decreases. Therefore, it does not represent an increasing linear function.

c) (1,-3),(3,5),(5,11),(7,18)
Here, as the x-coordinate increases from 1 to 3, the y-coordinate increases from -3 to 5. Continuing further, as the x-coordinate increases from 3 to 5, the y-coordinate increases from 5 to 11. This pattern shows consistent positive increments in the y-coordinate as the x-coordinate increases, which indicates an increasing linear function. Therefore, this data set does represent an increasing linear function.

d) (1,17),(2,15),(3,11),(4,3)
In this set, the y-coordinate decreases as the x-coordinate increases, which means it does not represent an increasing linear function.

So, based on our analysis, your answer is correct. Option c) (1,-3),(3,5),(5,11),(7,18) is the data set that represents an increasing linear function.