Question 1198314

assuming you need an equation of a line


({{{-1}}}, {{{-10}}}) ( {{{-1}}},{{{7}}}) 


first find a slope

{{{m=(y[2]-y[1])/(x[2]-x[1])}}}

{{{m=(7-(-10))/(-1-(-1))}}}

{{{m=(7+10)/(-1+1)}}}

{{{m=17/0}}}


Since the denominator is zero, the slope is {{{undefined}}} (remember you cannot divide by zero). 
So we cannot use the slope intercept form to write an equation. 
We can only say that the equation is a {{{vertical}}} line through {{{x=-1}}}, which means the equation is 

{{{x=-1 }}}(notice this is not in slope-intercept form)

The standard form for a vertical line is: {{{x+0*y=-1}}} or {{{x=-1 }}}

So the graph looks like this:

{{{ drawing( 600, 600, -10, 10, -15, 15,
circle(-1,-10,.12),circle(-1,7,.12),
locate(-1,-10,p(-1,-10)),locate(-1,7,p(-1,7)),
green(line(-1,15,-1,-15)),
graph( 600, 600, -10, 10, -15, 15, 0)) }}}