Find the area of the shaded region.

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postimg.o rg/image/dg4kt89v1/

Please help me explain this one. I know the ans to this one but can not work out.

User Icon for Reiny Reiny answered
10 years ago

you have to do in in two parts

we need the x-intercept:
0 = √x-3
√x = 3
x = 9

area from 0 to 9 + area from 9 to 16
(If you do it in one calculation from 0 to 16, the area which is below the x-axis will work its way into the answer as a negative area)

y = √x - 3
Area = ∫(-x^(1/2) + 3) dx from 0 to 9 + ∫(x^(1/2) - 3) dx from 9 to 16
= (-(2/3)x^(3/2) + 3x)|from 0 to 9 + ((2/3)x^(3/2) - 3x)| from 9 to 16
=(-2/3)(27) + 27 - 0 + (2/3)(64) - 48 - ((2/3)(27) - 27)
= -18 + 27 + 128/3 - 48 - 18 + 27
= 38/3