How to find the gradient of a perpendicular line? Please help completely stuck!?

The Gradient Of a Perpendicular line is known as m x m =-1

the gradient is 2 of the standard line sub 2 in so 2 x -1/2 = -1 so the perpendicular line has a gradient of of minus a half written in the form y=mx+c y=-1/2x+c.

so sub in points (2,2) for x and y like soo 2=-1/2(2)+c this is equal to 2=-3/2+c which c=5/2

so the equation of the perpendicular line is y=-1/2x+5/2

If you can find the slope (gradient) of a line, then you can find the slope of its perpendicular as the !inverse reciprocal".

inverse = change the sign (+ becomes -, for example)

reciprocal = flip the fraction (4 becomes 1/4)

Thus if you have a line like this

y = 7x - 4

the slope is 7

and the perpendicular's slope will be -1/7

(the constant term can be anything)

y = (-1/7)x - 52

is perpendicular

and it can be written in many other ways;

7y = -x - 52

x + 7y = -52

x + 7y + 52 = 0

and so on.

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slope is (diff. in y)/(diff. in x)

going from A to B, y goes down by 4, x goes down by 2

gradient (slope) = -4/-2 = 2

the perpendicular will be "inverse reciprocal" gradient = -1/2