1 99:59:59,999 --> 99:59:59,999 so we've got the function f of x is equal 2 99:59:59,999 --> 99:59:59,999 to x squared, and what I am concerned with is finding 3 99:59:59,999 --> 99:59:59,999 the area under the curve y is equal to f of x 4 99:59:59,999 --> 99:59:59,999 that's my y-axis, this is my 5 99:59:59,999 --> 99:59:59,999 my x-axis, they'll let me draw my function 6 99:59:59,999 --> 99:59:59,999 my function looks like this, at least in the 7 99:59:59,999 --> 99:59:59,999 first quadrant, that's why I'll graph it for now, I could also graph it on the 8 99:59:59,999 --> 99:59:59,999 in the second quadrant, but what I care about is the area 9 99:59:59,999 --> 99:59:59,999 under this curve and above the positive x-axis 10 99:59:59,999 --> 99:59:59,999 between x equals 1 and x 11 99:59:59,999 --> 99:59:59,999 equals 4, and I'm tired of 12 99:59:59,999 --> 99:59:59,999 approximating areas, I want to find the exact area under this curve 13 99:59:59,999 --> 99:59:59,999 above the x-axis, and the way we didn't know 14 99:59:59,999 --> 99:59:59,999 the exact area under the curve, this little brown shaded area 15 99:59:59,999 --> 99:59:59,999 is using the definite integral, the definite integral from 1 to 4