Question

The equation y = ax describes the graph of a line. If the value of a is positive, the line:

A. goes up and to the right.
B. is horizontal.
C. is vertical.
D. goes down and to the right.

Answer 1

i know its not d

Answer 2

'a' is the slope of the line which is the tangent of the angle the line makes with the positive x-axis. If 'a' is positive, then the tan(theta) is positive and 0 < theta < 90 degrees which implies ?

Answer 3

goes up

Answer 4

correct.

Answer 5

oh its going horizontal

Answer 6

its correct for sure you can cross check with y=2x

Answer 7

or y=x also where a=1, a line passing through origin making an angle equal to 45 deg with positive x axis, the most correct explanation.

Answer 8

Horizontal lines have zero slope.
Vertical lines have undefined slope.
A line that makes acute angle with the positive x-axis will have positive slope and the line goes up and to the right. (a > 0)
A line that makes an angle greater than 90 but less than 180 degrees with the positive x-axis will have negative slope and the line goes down and to the right. (a < 0).