The y-intercept formula is y = mx + b. b is the y-intercept. The line crosses the y-axis at 2, so the y-intercept is 2. m is the slope and it is rise/run (rise over run). It rises (from the y-axis) once and runs 4 times. Therefore, the slope is 1/4. The equation is f(x) = 1/4x +2.
