(5)
By giving different values to the parameters m and c, we get different members of
the family, e g ,
y = x
(m = 1,   c = 0)
y = 
3 x
(m = 
3 ,  c = 0)
y = x + 1
(m = 1,  c = 1)
y = – x
(m = – 1,  c = 0)
y = – x – 1
(m = – 1,  c = – 1) etc ( see Fig 9