Answer:
4.
f(x) = (x + 2)(x + 1)(x - 3) = x^3 - 7·x - 6
a = 0 ; b = -7 ; c = -6
5.
a = -3 ∧ b = -2 ∧ c = -3
Step-by-step explanation:
S = ∫ 2π y ds
ds = √(1 + (dx/dy)²) dy
ds = √(1 + (8y)²) dy
ds = √(1 + 64y²) dy
S = ∫₁² 2π y √(1 + 64y²) dy
S = π/64 ∫₁² 128y √(1 + 64y²) dy
S = π/64 [⅔ (1 + 64y²)^(³/₂)] |₁²
S = π/96 (1 + 64y²)^(³/₂) |₁²
S = π/96 (1 + 256)^(³/₂) − π/96 (1 + 64)^(³/₂)
S = π/96 (257√257) − π/96 (65√65)
S = π/96 (257√257 − 65√65)
13 By the factor theorem, if the function is divisible by x - 3 then f(3) = 0. So we have:-
2(3)^3 + k(3)^2 + 7(3) - 3 = 0
9k = 3 - 21 - 54 = -72
k = -72/9 = -8 answer
14. Similarly , f(-4) = 0 , so we have:-
(-4)^3 + 9(-4)^2 + k(-4) - 12 = 0
-64 + 144 - 4k - 12 = 0
4k = -64 + 144 - 12 = 68
k = 68/4
k = 17 answer
