How do i do slope of parallel lines and perpendicular lines?

Question

like if they give u 2 equations or an equation and point, or 3 points or etc

Answer 1

parallel lines have the same slope m2=m1

perpendicular lines have opposite, inverse slopes, m2= -1/m1

if the equations are in form y=mx+b, then the m in this equation is the slope.

If they give you two points on a line, then the slope is the ordered difference in y values over the ordered difference in x values:

m = (y2-y1) / (x2-x1)

Answer 2

To begin, the form of the equation in question should always be in slope-intercept form, which is y=mx+b, where m = the slope and b = the y intercept.

In this case, it is simple to finish up, because the slope of a parallel line equals m, and the slope of the perpendicular line is 1 divided by m or 1/m.

For each of the three scenarios you gave, there should be samples of how to find the value of m or how to convert the equation to slope-intercept form.

Answer 3

All you have to think about is this word association:

Parallel - "Same slope"

Perpendicular - "Negative reciprocal"

Thus, if you're asked to find the equation of a line parallel to y = 5x + 2 and through (1, 6), you would copy the line's slope.

If you're asked to find the equation of the line perpendicular to
y = 5x + 2 and through (1, 6), you would copy the slope's negative reciprocal; that is, you would take the reciprocal of the number (1/5) and then negate it (-1/5).

Answer 4

the slope S of line y = a + bx is -b/a

All parallel lines have the same slope

perpendicular lines will be the negative of this slope i.e. S = b/a

given this info you simply need to plug it in along with the given info if you are trying to construct a parallel or perpendicular line.

Answer 5

Parallel lines have the same gradient (slope) as another equation parallel to it.

Perpendicular lines have a negative reciprocal gradient, i.e. you turn the gradient upside down and change it's sign.

e.g. M (gradient) = 3

So the M perp = -1/3

e.g. M = -24/7

M perp = 7/24

easy!

Answer 6

slope of
parallel lines =0 [because tan0=0]
perpendicular lines=1 [because tan90=1]