What does c represent
The formula of a straight line is `y=mx+c`
`c` is the point where the straight line crosses the `y` axis (`y` intercept).
Do we need to remember this?
No because it is so easy to work out
`y=3x+1` is the formula of a straight line
If `x` is zero then:
The point where the slope hits the `y` axis is:
`x=0` and `y=1`
The point where the line hits the `x` axis is
If `y` is zero then:
The point where the line hits the `x` axis is:
`x=-1/3` and `y=0`