C H A P T E R 2 Polynomial and Rational Functions
C H A P T E R 2 Polynomial and Rational Functions
C H A P T E R 2 Polynomial and Rational Functions
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75. —CONTINUED—<br />
(d)<br />
A 8<br />
x50 x<br />
3<br />
8<br />
3 x2 50x<br />
8<br />
3 x2 50x 625 625<br />
8<br />
3 x 252 625<br />
8<br />
3 x 252 5000<br />
3<br />
The maximum area occurs at the vertex <strong>and</strong> is<br />
square feet. This happens when feet <strong>and</strong><br />
feet. The dimensions<br />
are feet by 33 feet.<br />
1<br />
50003<br />
x 25<br />
y 200 4253 1003<br />
2x 50<br />
76. (a) Radius of semicircular ends of track:<br />
Distance around two semicircular parts of track:<br />
d 2r 2 1<br />
r <br />
y y 2 1<br />
2 y<br />
77.<br />
(b) Distance traveled around track in one lap:<br />
d y 2x 200<br />
3<br />
y 200 2x<br />
y 4<br />
9 x2 24<br />
x 12<br />
9<br />
200 2x<br />
y <br />
<br />
Section 2.1 Quadratic <strong>Functions</strong> <strong>and</strong> Models 147<br />
(c) Area of rectangular region:<br />
200 2x<br />
A xy x<br />
2<br />
2<br />
2<br />
The area is maximum when <strong>and</strong><br />
200 250<br />
y 100<br />
x 50<br />
The vertex occurs at The maximum height is y3 feet.<br />
4<br />
9 32 24<br />
b 249<br />
3.<br />
3 12 16<br />
2a 249 9<br />
78. y <br />
(a) The ball height when it is punted is the y-intercept.<br />
16<br />
2025 x2 9<br />
x 1.5<br />
5<br />
y 16<br />
2025 02 9<br />
0 1.5 1.5 feet<br />
5<br />
(b) The vertex occurs at x b<br />
2a <br />
95<br />
2162025<br />
The maximum height is<br />
—CONTINUED—<br />
f 3645 16<br />
32 <br />
2025 3645<br />
32 2<br />
9<br />
5 3645<br />
32 1.5<br />
6561<br />
64<br />
6561<br />
32<br />
3645<br />
32 .<br />
1.5 6561<br />
64<br />
(e) They are all identical.<br />
feet <strong>and</strong> y 33 feet<br />
1<br />
x 25<br />
3<br />
1<br />
200x 2x2 <br />
<br />
13,122<br />
64<br />
<br />
<br />
x2 100x<br />
x2 100x 2500 2500<br />
x 502 5000<br />
<br />
96<br />
64<br />
.<br />
6657<br />
feet 104.02 feet.<br />
64