College Algebra & Trigonometry, 2018a

528 CHAPTER 11. THE LAW OF SINES THE LAW OF COSINES
Section 4.9(cont.)
Geometry/Cost Optimization
1) C(w) =20w 2 + 180
w
3) V (x) =300x − x3
4
l ≈ 3.302,w ≈ 1.651,h≈ 1.834 l = w =20
Minimum cost ≈ $163.54 Maximum volume = 4000cm 3
5) A(w) =
60 − 2w − πw
4
∗ w + πw2
8
7) V (x) =100r − πr 3
w ≈ 8.041,l≈ 4.201,A≈ 63.011ft 2 r ≈ 3.257,h≈ 6.516,V ≈ 217in 3
Distance Optimization
1) d(t) = √ 89t 2 3) d(t) = √ (9 − 15t) 2 +(2+12t) 2
d = 150m
t ≈ 15.9 sec
t ≈ 0.3hrs. → 1:18pm
d ≈ 7.2 miles
Distance/Time/Cost Optimization
1) t(x) = √ x 2 +2500+20− x 5
x ≈ 10.206
3) C(x) =25 √ x 2 + 3600 + 20(200 − x)
x =80→ 120m on land, 100m in the water
t ≈ 69 sec C(80) = $4900