Answer:
(√2 - √6) / 4
C. square root of two minus square root of six divided by four.
Step-by-step explanation:
sine of negative eleven pi divided by twelve.
We have :
sin(-11π/12)
sin((4 - 15)π / 12) = sin(4π/12 - 15π/12)
sin(4π/12 - 15π/12) = sin(π/3 - 5π/4)
Recall:
Angle difference formula:
sin(A - B) = sinAcosB - sinBcosA
Hence,
sin(π/3 - 5π/4) = sin(π/3) cos(5π/4) − sin(5π/4) cos(π/3)
From trigonometry:
sinπ/3 = √3/2
cos5π/4 = -√2/2
sin5π/4 = -√2/2
cos π/3 = 1/2
(√3/2) (-√2/2) − (-√2/2) (1/2)
-√6/4 - -√2/4
-√6/4 + √2/4
√2/4 - √6/4
(√2 - √6) / 4
Answer:
B. -2
Step-by-step explanation:
2(x - 4) + 3x - x2
2(2 - 4) + 3(2) - (2)2
2(-2) + 6 - 4
-4 + 6 - 4
-8 + 6
-2
We can create two equations here:
(1) Volume = area of square * height of box
85.75 = s^2 h
(2) Cost = 3 * area of square + 1.5 * area of side box
C = 3 s^2 + 1.5 s h
From (1), we get:
h = 85.75 / s^2
Combining this with (2):
C = 3 s^2 + 1.5 s (85.75 / s^2)
C = 3 s^2 + 128.625 s-
Taking the 1st derivative and equating dC/ds =
0:
dC/ds = 6s – 128.625 / s^2 = 0
Multiply all by s^2:
6s^3 – 128.625 = 0
6s^3 = 128.625
s = 2.78 cm
So h is:
h = 85.75 / s^2 = 85.75 / (2.78)^2
h = 11.10 cm
So the dimensions are 2.78 cm x 2.78 cm x 11.10 cm
The total cost now is:
C = 3 (2.78)^2 + 1.5 (2.78) (11.10)
C = $69.47
