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goldenfox [79]
3 years ago
11

Lowering powers write in terms of first power of cosine. Cos^6

Mathematics
1 answer:
yaroslaw [1]3 years ago
4 0

The main identity you need is the double angle one for cosine:

\cos^2x=\dfrac{1+\cos2x}2

We get

\cos^6x=(\cos^2x)^3=\left(\dfrac{1+\cos2x}2\right)^3=\dfrac{(1+\cos2x)^3}8

Expand the numerator to apply the identity again:

\cos^6x=\dfrac{1+3\cos2x+3\cos^22x+\cos^32x}8

\cos^6x=\dfrac{1+3\cos2x+3\left(\frac{1+\cos2(2x)}2\right)+\cos2x\left(\frac{1+\cos2(2x)}2\right)}8

\cos^6x=\dfrac{1+3\cos2x+\frac32+\frac32\cos4x+\frac12\cos2x(1+\cos4x)}8

\cos^6x=\dfrac5{16}+\dfrac7{16}\cos2x+\dfrac3{16}\cos4x+\dfrac1{16}\cos2x\cos4x

Finally, make use of the product identity for cosine:

\cos2x\cos4x=\dfrac{\cos6x+\cos2x}2

so that ultimately,

\cos^6x=\dfrac5{16}+\dfrac7{16}\cos2x+\dfrac3{16}\cos4x+\dfrac1{32}\cos2x+\dfrac1{32}\cos6x

\cos^6x=\dfrac5{16}+\dfrac{15}{32}\cos2x+\dfrac3{16}\cos4x+\dfrac1{32}\cos6x

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you minus them

Step-by-step explanation:

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3 years ago
A pickup truck carrying 10 to the 3rd power identical bricks weighs 6,755 pounds. If the empty truck weighs 6,240 pounds, what i
Aleks04 [339]

Answer:

The answer is that each brick weights .515 pounds.

Step-by-step explanation:

10 to the 3rd power is 10^3 = 1000 bricks.

The weight of the full truck minus the weight of the empty truck is the weight of the bricks:

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Pounds per brick:

515 / 1000 = .515 pounds per brick.

Hope this helps! Have a great day!

5 0
3 years ago
Zeke and Niko are eating cookies. The ratio of the number of cookies Zeke ate to the number Niko ate was 2 to 1 (so Zeke had twi
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6

Step-by-step explanation:

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2 years ago
Rewrite <br> 16/9<br> as a mixed number.
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3 0
3 years ago
Read 2 more answers
Find the surface area of the composite figure. Round to the nearest square centimeter
Goryan [66]

Answer:

Surface area = 726 cm²

None of the options is correct.

Step-by-step explanation:

Surface area of the composite figure = surface area of cone + surface area of cylinder - 2(area of base of cone)

✔️Surface area of cone = πr(r + l)

Where,

Radius (r) = 5 cm

Slant height (l) = √(10² + 5²) (Pythagorean theorem)

Slant height (l) = 11.2 cm

Plug in the values

= π*5(5 + 11.2)

= 254.5 cm²

✔️Surface area of the cylinder = 2πr(h + r)

r = 5 cm

h = 15 cm

Plug in the values into the formula

S.A = 2*π*5(15 + 5)

S.A = 628.3 cm²

✔️area of base of cone = πr²

r = 5 cm

Area = π*5² = 78.5 cm²

✅Surface area of the composite figure = 254.5 + 628.3 - 2(78.5)

= 882.8 - 157

= 726 cm² (nearest square meter)

None of the options is correct.

7 0
3 years ago
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