range [0,4]

0 <= f'(x) <=3

what is the maximum point?

so, I assume x=3 when f'(x)=4 (assuming some sort of f(x) curving upwards with the tangent slopes increasing from 0). Not sure how to get y from there.

maybe tanget line...y=mx+b...y=(4)(3)+b...y=12+b

but then what is the y-intercept, b? two unknowns.

been struggling with this without a function. Thank you for any help.