Page 211 - How To Solve Word Problems In Calculus

P1: FYN/FZQ P2: FXS
PB056-07 Macros-FMT June 1, 2001 13:49 Char Count= 0

y 2 − y 1 is still positive throughout the region since y 1 is more negative
than y 2 . This guarantees that the integral will represent the area.)

1

A = (y 2 − y 1 ) dx
−1
1

= 2 (y 2 − y 1 ) dx
0
1

4
2
2
= 2 [(x − x ) − (x − 1)] dx
0
1

4
2
= 2 (x − 2x + 1) dx
0
5 3 1
x 2x
= 2 − + x
5 3
0

1 2
= 2 − + 1 − 0
5 3

8
= 2
15
16
=
15
5.
6 6

4 4
(x,y)
2 2 1 (x,y)
2

1 1 2 2 3 3 4 4 5 5
− 2
−2

− 4
−4

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