I understand when its parallel the slope is the same but what is the slope when its perpendicular?

is the answer..

y=4x-6

y=-4x-6

y=-4x + 2

y=4x

I understand when its parallel the slope is the same but what is the slope when its perpendicular?

is the answer..

y=4x-6

y=-4x-6

y=-4x + 2

y=4x

Tutors, please sign in to answer this question.

In the equation,

y = 1/4x + 2, which is of the form y = mx+b,

m (the slope) = 1/4. Any parallel line will have the same slope, as you properly stated. A perpendicular slope is the negative inverse of the original (reciprocal with opposite sign). In this case it would be -4.

The equation of our line is given as y=mx+b. In this case, our slope m is equal to 1/4 and our y intercept b is equal to 2.

Now, to find the line perpendicular to this first given line, our slope will have to be the
**negative** reciprocal of the given slope. Our new slope for this line is then -1/(1/4) = -4.

To come up with an equation for this line, the problem has supplied us with a point that it must pass through. We have a handy
*point slope form* equation that we can plug our information into to get an equation in the desired form.

Point Slope Form, for a slope m and given point (x1,y1) is given as:

y-y1 = m(x-x1)

Let's plug in our info. Our new slope is m = -4 and our point is (x1,y1)=(-1,-2)

y-(-2) = -4(x-(-1))

y+2 = -4(x+1)

y+2 = -4x-4

y = -4x-6 <-- answer

So if your answer choices are A, B, C, D - it would be choice B.

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