Answer:
<u>Step-by-step explanation:</u>
Note the following identities: tan² x = sec²x - 1
tan² x + sec x = 1
(sec² x -1) + sec x = 1
sec² x + sec x - 2 = 0
(sec x + 2)(sec x - 1) = 0
sec x + 2 = 0 sec x - 1 = 0
sec x = -2 sec x = 1
Answer:
The cost of the material for the full-sized pad is;
d) 222,750.00
Step-by-step explanation:
The parameters of the steel pad and the scale model are;
The volume of the deck = 18 yd³
The dimensions of the model of the same material = 6 feet by 4.5 feet and 4.5 inches thick
The weight of the sample, m₂ = 75 lbs
The cost of the steel, P = $55/lb
The dimensions of the sample in yards are;
6 feet = 2 yards, 4.5 feet = 1.5 yards, and 4 inches = 0. yards
The volume of the sample, V₂ = 2 yd. × 1.5 yd. × 0. yd. = (1/3) yd.³
The density of the sample material, ρ = m₂/V₂
∴ The density of the sample material, ρ = 75 lbs/((1/3)yd.³) = 225 lbs/yd³
Therefore, the density of the material of the pad, ρ = 225 lbs/yd³
The mass of the steel pad, m₁ = ρ × V₁
∴ The mass of the steel pad, m₁ = 225 lbs/yd³ × 18 yd³ = 4,050 lbs
The cost of the material for the full-sized steel pad, C = m₁ × P
∴ C = 4,050 lbs × $55/lb = $222,750