- #1

mimi.janson

- 80

- 0

## Homework Statement

Hi i have a circle that is shown by (x-7)

^{2}+(y+1)

^{2}=20

i also have a line y=2x-5 and i have to explain why the line is a tangent to the edge of the circle

i know that the circle has the centre in (7,1) and that the radius of it is 4,4

## Homework Equations

i know i have to use the formula G =l ad+be+c l/√a

^{2}+b

^{2}

where the result should be something like the centre +4,4

## The Attempt at a Solution

i have tried to change my y=2x-5 so it stands in the form ax+by+c=0 and i think it will end up like 2x+1y+(-5)=0 but i really don't know what to do next. I have attached a photo of what i mean with the tangent. the one that i am speaking about is the red