Question 433112
First put the equation 2x-4y=9 in standard form:
y = 1/2x - 9/4
The slope of the perpendicular line is the negative reciprocal of 1/2 = -2 (you were correct!)
The point-slope form for a line is:
y - y1 = m(x - x1)
Using the point (x1,y1) = (-1/4,1/2) we get:
y - 1/2 = -2(x - -1/4)
This gives y = -2x
So, the y-intercept is 0 (you were correct!)
The lines are shown below:
{{{graph(300,300,-10,10,-10,10,x/2-9/4,-2x)}}}