## Labels

### Introduction To Functions - 3ºeso

FUNCTIONS

1. Fill in the gaps.

When working with equations that have two (1)__________, the coordinate plane is an important tool. It's a way to draw pictures of equations that makes them easier to understand.

To create a coordinate plane, start with a sheet of graph paper. Next, draw a (2)__________ line. This line is called the x-axis and is used to locate values of x. To show that the axis actually goes on forever in both directions, use small arrowheads at each end of the line. Mark off a number line with (3)__________ in the center, positive numbers to the (4)__________, and negative numbers to the (5)__________.

Next draw a (6)__________ line that intersects the x axis at zero. This line is called the y-axis and is used to locate the values of y. Mark off a number line with zero in the center, (7)__________ numbers going upwards, and (8)__________ numbers going downwards. The point where the x and y axes intersect is called the origin. The origin is located at (9)__________ on the x axis and zero on the y axis.

Locating Points Using Ordered Pairs
We can locate any point on the coordinate plane using an ordered pair of numbers. We call the ordered pair the coordinates of the point. The coordinates of a point are called an ordered pair because the order of the two (10)__________ is important.

The first number in the ordered pair is the (11)__________ coordinate. It describes the number of units to the left or right of the origin. The second number in the ordered pair is the (12)__________ coordinate. It describes the number of units above or below the origin. To plot a point, start at the (13)__________ and count along the x axis until you reach the x coordinate, count right for positive numbers, left for negative. Then count up or down the number of the y coordinate (up for (14)__________, down for (15)__________.)

Quadrants
To make it easy to talk about where on the coordinate plane a point is, we divide the coordinate plane into four sections called quadrants.

Points in Quadrant 1 have positive x and positive y coordinates.
Points in Quadrant 2 have (16)__________ x but (17)__________ y coordinates.
Points in Quadrant 3 have (18)__________ x and (19)__________ y coordinates.
Points in Quadrant 4 have (20)__________ x but (21)__________ y coordinates.

horizontal   left   negative   negative   negative   negative   negative   negative   numbers   origin   positive   positive   positive   positive   right   variables   vertical   x   y   zero   zero

2. Match each word with its translation in Spanish.

COORDINATE PLANE                                             EJES CARTESIANOS
DEPENDENT VARIABLE                                        VARIABLE DEPENDIENTE
INDEPENDENT VARIABLE                                     FUNCIÓN
FUNCTION                                                               PAR ORDENADO
SET OF POINTS                                                        VARIABLE INDEPENDIENTE

3. Complete the Crossword.

### Across:

1
The steepness or slant o a line
3
The horizontal number line on a coordinate plane
4
The vertical number line on a coordinate plane
5
The value of y at the point where the line crosses the y axis

### Down:

2
The equation of any straight line