Point slope form

Question

Through (4,-4) slope=-2

Answer 1

Hi,

Through (4,-4) slope=-2

For writing an equation of line through of point by having slope there are two

methods:

First: slope form of equation is y = mx + b that you need to know m (slope) and b

in this case you know m = -2 then replace given information to the equation then you find b

y = mx + b ===> -4 = 4 * (-2) + b ====> b = 4 so y = -2x + 4

Second method: you can use y-y₁= m ( x - x₁) that (x₁,y₁) is given point

y-y₁= m ( x - x₁) ===> y - (-4) = -2( x- 4) ===> y + 4 = -2x +8==> y = -2x +4

The same result.

I hope it is useful,

Minoo