# Thread: coordinate plane graphing problem

1. ## coordinate plane graphing problem

The function values for h(x) vary directly as x for all real numbers. The graph of y = h(x) in the standard (x,y) coordinate plane is:

a line with a y-intercept at 0.

How do they get this solution and why can't it be the other possible solutions which are:

a line with a y-intercept but not at 0
a line with no y-intercept
a hyperbola
neither a line nor a hyperbola

2. Originally Posted by sarahh
The function values for h(x) vary directly as x for all real numbers. The graph of y = h(x) in the standard (x,y) coordinate plane is:

a line with a y-intercept at 0.

How do they get this solution and why can't it be the other possible solutions which are:

a line with a y-intercept but not at 0
a line with no y-intercept
a hyperbola
neither a line nor a hyperbola
h(x) varies directly as x so the equation for h(x) must be
$\displaystyle h(x) = ax$
where a is some constant.

This is the definition of "varies directly."

-Dan