Answer:
[tex]y = 2x -4[/tex]
Step-by-step explanation:
[tex]y = -\frac{1}{2}x - 2\ \ \ \ \ \ (0, -4)[/tex]
To find the perpendicular equation of a line,
You need the product of their gradients to be -1
[tex]-\frac{1}{2} \times ? = -1[/tex]
Divide both sides by [tex]-\frac{1}{2}[/tex]
? = 2
The gradient of the perpendicular line is 2
Straight line formula is in the form [tex]y = mx + c[/tex]
[tex]y = 2x + c[/tex]
We're nearly there, we just need to find out c.
Luckily, we're given a point [tex](0, -4)[/tex]
[tex](x, y) = (0, -4)[/tex]
[tex]y = 2x + c[/tex]
[tex]-4 = 2(0) + c\\-4 = 0 + c\\c = -4[/tex]
We then end up with...
[tex]y = 2x -4[/tex]
