The equation of the line, \[ y=3 x \] is a horizontal line. True False

Step 1 ：The equation given is y = 3x. This is the equation of a line in slope-intercept form, y = mx + b, where m is the slope of the line and b is the y-intercept.

Step 2 ：In this case, the slope of the line is 3, which means the line is not horizontal.

Step 3 ：A horizontal line would have a slope of 0.

Step 4 ：Therefore, the statement 'The equation of the line, y=3x, is a horizontal line' is false.

Step 5 ：Final Answer: \(\boxed{\text{False}}\).