Write an equation of a line in slope intercept form that is perpendicular to y = -4x -2 and passes through the point (-16, -11).

Question

slaaibak · Answer

If lines are perpendicular, m1 * m2 = -1

That's how you will find the slope of the line.  Once you have the slope, use this formula:

$$y - y_1 = m(x - x_1)$$

anonymous · Answer

But isn't the slope intercept formula y = mx + b?

slaaibak · Answer

Once you plug in the values m, y1 and x1, you will be able to write it in the form of y = mx + b

anonymous · Answer

Ah, well thank you then!

slaaibak · Answer

I'll demonstrate:

Slope of the line you need to find = 1/4, since -4 * 1/4 = -1

Now, you have m=1/4

you have the point (-16, -11)

Using my formula:

y - (-11) = 1/4 (x - (-16))
y + 11 = 1/4x + 4
y=1/4x - 7

anonymous · Answer

Okay, thank you. That makes a lot more sense c:

anonymous · Answer

But where did the 1/4 come from exactly?

slaaibak · Answer

The lines are perpendicular.  slope of line1 * slope of line 2 = -1

That's a rule for lines to be perpendicular.

now you have the slope of line 1:

-4 * m2 = -1
m2 = -1/-4 = 1/4

anonymous · Answer

Oh okay, that makes sense. Thank you.