What is the value of ((2*5*4pi*cos^2(4pi*0.3)))/(1000) ?

The value of ((2*5*4pi*cos^2(4pi*0.3)))/(1000) is (pi(3+sqrt(5)))/(200)

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Popular Trigonometry >

((254picos^2(4pi0.3)))/(1000)

Solution

\frac{( 2 \cdot 5 \cdot 4 π \cdot cos ^{2} ( 4 π \cdot 0.3 ) )}{1000}

Solution

\frac{π ( 3 + 5 )}{200}

Decimal

0.08224 \dots

Solution steps

\frac{( 2 \cdot 5 \cdot 4 π cos ^{2} ( 4 π 0.3 ) )}{1000}

= \frac{2 \cdot 5 \cdot 4 π cos ^{2} ( 4 π \frac{3}{10} )}{1000}

Simplify:

4 π \frac{3}{10} = \frac{6 π}{5}

4 π \frac{3}{10}

Multiply fractions:

a \cdot \frac{b}{c} = \frac{a \cdot b}{c}

= \frac{3 \cdot 4 π}{10}

Multiply the numbers:

3 \cdot 4 = 12

= \frac{12 π}{10}

Cancel the common factor:

2

= \frac{6 π}{5}

\frac{2 \cdot 5 \cdot 4 π cos ^{2} ( \frac{6 π}{5} )}{1000} = \frac{π cos ^{2} ( \frac{6 π}{5} )}{25}

\frac{2 \cdot 5 \cdot 4 π cos ^{2} ( \frac{6 π}{5} )}{1000}

Multiply the numbers:

2 \cdot 5 \cdot 4 = 40

= \frac{40 π cos ^{2} ( \frac{6 π}{5} )}{1000}

Cancel the common factor:

40

= \frac{π cos ^{2} ( \frac{6 π}{5} )}{25}

= \frac{π cos ^{2} ( \frac{6 π}{5} )}{25}

Rewrite using trig identities:

cos (\frac{6 π}{5}) = - \frac{5 + 1}{4}

cos (\frac{6 π}{5})

Rewrite using trig identities:

cos (\frac{4 π}{5})

cos (\frac{6 π}{5})

Use the following identity:

cos (x) = cos (2 π - x)

cos (x)

Use the following property:

cos (θ) = cos (- θ)

cos (x) = cos (- x)

= cos (- x)

Apply the periodicity of

cos

cos (2 π + θ) = cos (θ)

cos (- x) = cos (2 π - x)

= cos (2 π - x)

= cos (2 π - \frac{6 π}{5})

Simplify:

2 π - \frac{6 π}{5} = \frac{4 π}{5}

2 π - \frac{6 π}{5}

Convert element to fraction:

2 π = \frac{2 π 5}{5}

= \frac{2 π 5}{5} - \frac{6 π}{5}

Since the denominators are equal, combine the fractions:

\frac{a}{c} \pm \frac{b}{c} = \frac{a \pm b}{c}

= \frac{2 π 5 - 6 π}{5}

2 π 5 - 6 π = 4 π

2 π 5 - 6 π

Multiply the numbers:

2 \cdot 5 = 10

= 10 π - 6 π

Add similar elements:

10 π - 6 π = 4 π

= 4 π

= \frac{4 π}{5}

= cos (\frac{4 π}{5})

= cos (\frac{4 π}{5})

Rewrite using trig identities:

- cos (\frac{π}{5})

cos (\frac{4 π}{5})

Use the basic trigonometric identity:

cos (x) = - cos (π - x)

= - cos (π - \frac{4 π}{5})

Simplify:

π - \frac{4 π}{5} = \frac{π}{5}

π - \frac{4 π}{5}

Convert element to fraction:

π = \frac{π 5}{5}

= \frac{π 5}{5} - \frac{4 π}{5}

Since the denominators are equal, combine the fractions:

\frac{a}{c} \pm \frac{b}{c} = \frac{a \pm b}{c}

= \frac{π 5 - 4 π}{5}

Add similar elements:

5 π - 4 π = π

= \frac{π}{5}

= - cos (\frac{π}{5})

= - cos (\frac{π}{5})

Rewrite using trig identities:

cos (\frac{π}{5}) = \frac{5 + 1}{4}

cos (\frac{π}{5})

Show that:

cos (\frac{π}{5}) - sin (\frac{π}{10}) = \frac{1}{2}

Use the following product to sum identity:

2 sin (x) cos (y) = sin (x + y) - sin (x - y)

2 cos (\frac{π}{5}) sin (\frac{π}{10}) = sin (\frac{3 π}{10}) - sin (\frac{π}{10})

Show that:

2 cos (\frac{π}{5}) sin (\frac{π}{10}) = \frac{1}{2}

Use the Double Angle identity:

sin (2 x) = 2 sin (x) cos (x)

sin (\frac{2 π}{5}) = 2 sin (\frac{π}{5}) cos (\frac{π}{5})

sin (\frac{2 π}{5}) sin (\frac{π}{5}) = 4 sin (\frac{π}{5}) sin (\frac{π}{10}) cos (\frac{π}{5}) cos (\frac{π}{10})

Divide both sides by

sin (\frac{π}{5})

sin (\frac{2 π}{5}) = 4 sin (\frac{π}{10}) cos (\frac{π}{5}) cos (\frac{π}{10})

Use the following identity:

sin (x) = cos (\frac{π}{2} - x)

sin (\frac{2 π}{5}) = cos (\frac{π}{2} - \frac{2 π}{5})

cos (\frac{π}{2} - \frac{2 π}{5}) = 4 sin (\frac{π}{10}) cos (\frac{π}{5}) cos (\frac{π}{10})

cos (\frac{π}{10}) = 4 sin (\frac{π}{10}) cos (\frac{π}{5}) cos (\frac{π}{10})

Divide both sides by

cos (\frac{π}{10})

1 = 4 sin (\frac{π}{10}) cos (\frac{π}{5})

Divide both sides by

2

\frac{1}{2} = 2 sin (\frac{π}{10}) cos (\frac{π}{5})

Substitute

\frac{1}{2} = 2 sin (\frac{π}{10}) cos (\frac{π}{5})

\frac{1}{2} = sin (\frac{3 π}{10}) - sin (\frac{π}{10})

sin (\frac{3 π}{10}) = cos (\frac{π}{2} - \frac{3 π}{10})

\frac{1}{2} = cos (\frac{π}{2} - \frac{3 π}{10}) - sin (\frac{π}{10})

\frac{1}{2} = cos (\frac{π}{5}) - sin (\frac{π}{10})

Show that:

cos (\frac{π}{5}) + sin (\frac{π}{10}) = \frac{5}{4}

Use the factorization rule:

a^{2} - b^{2} = (a + b) (a - b)

a = cos (\frac{π}{5}) + sin (\frac{π}{10})

(cos (\frac{π}{5}) + sin (\frac{π}{10}))^{2} - (cos (\frac{π}{5}) - sin (\frac{π}{10}))^{2} = ((cos (\frac{π}{5}) + sin (\frac{π}{10})) + (cos (\frac{π}{5}) - sin (\frac{π}{10}))) ((cos (\frac{π}{5}) + sin (\frac{π}{10})) - (cos (\frac{π}{5}) - sin (\frac{π}{10})))

Refine

(cos (\frac{π}{5}) + sin (\frac{π}{10}))^{2} - (cos (\frac{π}{5}) - sin (\frac{π}{10}))^{2} = 2 (2 cos (\frac{π}{5}) sin (\frac{π}{10}))

Show that:

2 cos (\frac{π}{5}) sin (\frac{π}{10}) = \frac{1}{2}

Use the Double Angle identity:

sin (2 x) = 2 sin (x) cos (x)

sin (\frac{2 π}{5}) = 2 sin (\frac{π}{5}) cos (\frac{π}{5})

sin (\frac{2 π}{5}) sin (\frac{π}{5}) = 4 sin (\frac{π}{5}) sin (\frac{π}{10}) cos (\frac{π}{5}) cos (\frac{π}{10})

Divide both sides by

sin (\frac{π}{5})

sin (\frac{2 π}{5}) = 4 sin (\frac{π}{10}) cos (\frac{π}{5}) cos (\frac{π}{10})

Use the following identity:

sin (x) = cos (\frac{π}{2} - x)

sin (\frac{2 π}{5}) = cos (\frac{π}{2} - \frac{2 π}{5})

cos (\frac{π}{2} - \frac{2 π}{5}) = 4 sin (\frac{π}{10}) cos (\frac{π}{5}) cos (\frac{π}{10})

cos (\frac{π}{10}) = 4 sin (\frac{π}{10}) cos (\frac{π}{5}) cos (\frac{π}{10})

Divide both sides by

cos (\frac{π}{10})

1 = 4 sin (\frac{π}{10}) cos (\frac{π}{5})

Divide both sides by

2

\frac{1}{2} = 2 sin (\frac{π}{10}) cos (\frac{π}{5})

Substitute

2 cos (\frac{π}{5}) sin (\frac{π}{10}) = \frac{1}{2}

(cos (\frac{π}{5}) + sin (\frac{π}{10}))^{2} - (cos (\frac{π}{5}) - sin (\frac{π}{10}))^{2} = 1

Substitute

cos (\frac{π}{5}) - sin (\frac{π}{10}) = \frac{1}{2}

(cos (\frac{π}{5}) + sin (\frac{π}{10}))^{2} - (\frac{1}{2})^{2} = 1

Refine

(cos (\frac{π}{5}) + sin (\frac{π}{10}))^{2} - \frac{1}{4} = 1

Add

\frac{1}{4}

to both sides

(cos (\frac{π}{5}) + sin (\frac{π}{10}))^{2} - \frac{1}{4} + \frac{1}{4} = 1 + \frac{1}{4}

Refine

(cos (\frac{π}{5}) + sin (\frac{π}{10}))^{2} = \frac{5}{4}

Take the square root of both sides

cos (\frac{π}{5}) + sin (\frac{π}{10}) = \pm \frac{5}{4}

cos (\frac{π}{5})

cannot be negative

sin (\frac{π}{10})

cannot be negative

cos (\frac{π}{5}) + sin (\frac{π}{10}) = \frac{5}{4}

Add the following equations

cos (\frac{π}{5}) + sin (\frac{π}{10}) = \frac{5}{2}

((cos (\frac{π}{5}) + sin (\frac{π}{10})) + (cos (\frac{π}{5}) - sin (\frac{π}{10}))) = (\frac{5}{2} + \frac{1}{2})

Refine

cos (\frac{π}{5}) = \frac{5 + 1}{4}

= \frac{5 + 1}{4}

= - \frac{5 + 1}{4}

= \frac{π ( - \frac{5 + 1}{4} ) ^{2}}{25}

Simplify

\frac{π ( - \frac{5 + 1}{4} ) ^{2}}{25} : \frac{π ( 3 + 5 )}{200}

\frac{π ( - \frac{5 + 1}{4} ) ^{2}}{25}

π (- \frac{5 + 1}{4})^{2} = π (\frac{5 + 1}{4})^{2}

π (- \frac{5 + 1}{4})^{2}

(- \frac{5 + 1}{4})^{2} = (\frac{5 + 1}{4})^{2}

(- \frac{5 + 1}{4})^{2}

Apply exponent rule:

(- a)^{n} = a^{n},

n

is even

(- \frac{1 + 5}{4})^{2} = (\frac{5 + 1}{4})^{2}

= (\frac{5 + 1}{4})^{2}

= π (\frac{1 + 5}{4})^{2}

= \frac{π ( \frac{1 + 5}{4} ) ^{2}}{25}

(\frac{5 + 1}{4})^{2} = \frac{3 + 5}{2 ^{3}}

(\frac{5 + 1}{4})^{2}

Apply exponent rule:

(\frac{a}{b})^{c} = \frac{a ^{c}}{b ^{c}}

= \frac{( 5 + 1 ) ^{2}}{4 ^{2}}

(5 + 1)^{2} = 6 + 25

(5 + 1)^{2}

Apply Perfect Square Formula:

(a + b)^{2} = a^{2} + 2 ab + b^{2}

a = 5, b = 1

= (5)^{2} + 25 \cdot 1 + 1^{2}

Simplify

(5)^{2} + 25 \cdot 1 + 1^{2} : 6 + 25

(5)^{2} + 25 \cdot 1 + 1^{2}

Apply rule

1^{a} = 1

1^{2} = 1

= (5)^{2} + 2 \cdot 1 \cdot 5 + 1

(5)^{2} = 5

(5)^{2}

Apply radical rule:

a = a^{\frac{1}{2}}

= (5^{\frac{1}{2}})^{2}

Apply exponent rule:

(a^{b})^{c} = a^{b c}

= 5^{\frac{1}{2} \cdot 2}

\frac{1}{2} \cdot 2 = 1

\frac{1}{2} \cdot 2

Multiply fractions:

a \cdot \frac{b}{c} = \frac{a \cdot b}{c}

= \frac{1 \cdot 2}{2}

Cancel the common factor:

2

= 1

= 5

25 \cdot 1 = 25

25 \cdot 1

Multiply the numbers:

2 \cdot 1 = 2

= 25

= 5 + 25 + 1

Add the numbers:

5 + 1 = 6

= 6 + 25

= 6 + 25

= \frac{6 + 2 5}{4 ^{2}}

Factor

6 + 25 : 2 (3 + 5)

6 + 25

Rewrite as

= 2 \cdot 3 + 25

Factor out common term

2

= 2 (3 + 5)

= \frac{2 ( 3 + 5 )}{4 ^{2}}

Factor

4^{2} : 2^{4}

Factor

4 = 2^{2}

= (2^{2})^{2}

Simplify

(2^{2})^{2} : 2^{4}

(2^{2})^{2}

Apply exponent rule:

(a^{b})^{c} = a^{b c}

= 2^{2 \cdot 2}

Multiply the numbers:

2 \cdot 2 = 4

= 2^{4}

= 2^{4}

= \frac{2 ( 3 + 5 )}{2 ^{4}}

Cancel the common factor:

2

= \frac{3 + 5}{2 ^{3}}

= \frac{π \frac{3 + 5}{2 ^{3}}}{25}

Multiply

π \frac{3 + 5}{2 ^{3}} : \frac{π ( 3 + 5 )}{8}

π \frac{3 + 5}{2 ^{3}}

Multiply fractions:

a \cdot \frac{b}{c} = \frac{a \cdot b}{c}

= \frac{( 3 + 5 ) π}{2 ^{3}}

2^{3} = 8

= \frac{π ( 3 + 5 )}{8}

= \frac{\frac{π ( 3 + 5 )}{8}}{25}

Apply the fraction rule:

\frac{\frac{b}{c}}{a} = \frac{b}{c \cdot a}

= \frac{( 3 + 5 ) π}{8 \cdot 25}

Multiply the numbers:

8 \cdot 25 = 200

= \frac{π ( 3 + 5 )}{200}

= \frac{π ( 3 + 5 )}{200}

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Frequently Asked Questions (FAQ)

What is the value of ((2*5*4pi*cos^2(4pi*0.3)))/(1000) ?
The value of ((2*5*4pi*cos^2(4pi*0.3)))/(1000) is (pi(3+sqrt(5)))/(200)