Question

Line Lis perpendicular to the y-axis. If the line contains point(0, -9), what is the equation of Line ?

O1
y = 0
2
x = 0
O
a
3
X = -9
4
y = -9

Answer 1

y = -9

Explanation:

perpendicular to the y-axis means it is parallel to the x-axis.

so, it is a flat line, which means the slope is 0 (it has the save y value for every x value).

therefore the equation is

y = 0×x + b

of simply

y = b

to get b we look at the point we know about (0, -9).

-9 = b

aha !

so, the line equation is simply

y = -9