My estimated answer for 1 is x=1.59 or x=-1.26 and my exact answer is (in word form) x= 1 plus or minus the square root of 73 over 6. my estimated answer for 2 is x=-0.34 or x=1.74 and my exact answer (in word form) is x= -7 plus or minus the square root of 109 over -10. I took a picture of my work and hopefully you can read it
Lateral area: 339.29
surface area: 565.49
The left sum would be f0+f1+f2+f3
The right sum would be f1+f2+f3+f4
The trapezoidal rule value is:
(f0+f1)/2 + (f1+f2)/2+(f2+f3)/2 +(f3+f4)/2
This would put the trapezoidal rule in the middle , which makes the answer:
Lower sum < Trapezoidal rule Value < Upper sum
Width = W
Length = 2 times the width plus 3 feet = 2W + 3
Area of triangle A = L * W
A = W (2W + 3)
20 = 2W^2 + 3W
2W^2 + 3W - 20 = 0
(W + 4) (2W - 5) = 0
W + 4 = 0; W = - 4 (width cannot be negative, excluded)
2W - 5 = 0
2W = 5
W = 2.5
L = 2W + 3 = 2(2.5) + 3 = 8
Answer:
Width = 2.5 feet and Length = 8 feet
Hope it helps.