text: plz help, what's the answer (area)? i don't understand this at all, plez hp:  there's a fcn f,  f starts at 20, and isn't going up and until the end... at 50. there's a fcn f,  f starts at 20,, and goes up and until the end, at 50.  is the area more or less at the start? if i'm reading this right, your two functions start at 20 and end at 50. the first one goes up slowly following a curve, like a skateboarder's ramp. the second goes up faster, like a slide.  i would guess that there would be more area at the start of the second function than the first. if you tried to draw a picture of what these functions are doing, and then you put them on top of each other, then you'd see that the slide function covers more area than the ramp function at the start. you can go further and say that the slide function has more area from 20 to 50 than the ramp function, again based on the overlapping drawings.  now, if you had actual functions, then we can find out exactly what the areas are by taking integrals of the functions from 20 to 50 (or 20 to 25, if you're still looking at the start). an integral is useful in finding areas under curves that traditional geometric formulas can't handle.