Given:
f(1) = 1 and f(-3) = 17
To find:
The lines function f.
Solution:
If f(a) = b, it means the function f passes through (a,b).
Here, f(1) = 1, it means the function f passes through (1,1).
f(-3) = 17, it means the function f passes through (-3,17).
If a linear function passes through two point
, then the equation of line is

The linear function f passes through (1,1) amd (-3,17). So, the equation of linear function is




Add 1 on both sides.


Put y=f(x), to write in function notation.

Therefore, required lines function is
.