What is the value of csc((2pi)/3)-cos((5pi)/4)+sin(pi/6) ?

The value of csc((2pi)/3)-cos((5pi)/4)+sin(pi/6) is (4sqrt(3)+3+3sqrt(2))/6

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Popular Trigonometry >

csc((2pi)/3)-cos((5pi)/4)+sin(pi/6)

Solution

csc (\frac{2 π}{3}) - cos (\frac{5 π}{4}) + sin (\frac{π}{6})

Solution

\frac{4 3 + 3 + 3 2}{6}

Decimal

2.36180 \dots

Solution steps

csc (\frac{2 π}{3}) - cos (\frac{5 π}{4}) + sin (\frac{π}{6})

Rewrite using trig identities:

csc (\frac{2 π}{3}) = \frac{2 3}{3}

csc (\frac{2 π}{3})

Rewrite using trig identities:

\frac{1}{sin ( \frac{2 π}{3} )}

csc (\frac{2 π}{3})

Use the basic trigonometric identity:

csc (x) = \frac{1}{sin ( x )}

= \frac{1}{sin ( \frac{2 π}{3} )}

= \frac{1}{sin ( \frac{2 π}{3} )}

Use the following trivial identity:

sin (\frac{2 π}{3}) = \frac{3}{2}

sin (\frac{2 π}{3})

sin (x)

periodicity table with

2 πn

cycle:

x 0 \frac{π}{6} \frac{π}{4} \frac{π}{3} \frac{π}{2} \frac{2 π}{3} \frac{3 π}{4} \frac{5 π}{6} sin (x) 0 \frac{1}{2} \frac{2}{2} \frac{3}{2} 1 \frac{3}{2} \frac{2}{2} \frac{1}{2} x π \frac{7 π}{6} \frac{5 π}{4} \frac{4 π}{3} \frac{3 π}{2} \frac{5 π}{3} \frac{7 π}{4} \frac{11 π}{6} sin (x) 0 - \frac{1}{2} - \frac{2}{2} - \frac{3}{2} - 1 - \frac{3}{2} - \frac{2}{2} - \frac{1}{2}

= \frac{3}{2}

= \frac{1}{\frac{3}{2}}

Simplify

\frac{1}{\frac{3}{2}} : \frac{2 3}{3}

\frac{1}{\frac{3}{2}}

Apply the fraction rule:

\frac{1}{\frac{b}{c}} = \frac{c}{b}

= \frac{2}{3}

Rationalize

\frac{2}{3} : \frac{2 3}{3}

\frac{2}{3}

Multiply by the conjugate

\frac{3}{3}

= \frac{2 3}{3 3}

33 = 3

33

Apply radical rule:

a a = a

33 = 3

= 3

= \frac{2 3}{3}

= \frac{2 3}{3}

= \frac{2 3}{3}

Rewrite using trig identities:

cos (\frac{5 π}{4}) = - \frac{2}{2}

cos (\frac{5 π}{4})

Rewrite using trig identities:

cos (π) cos (\frac{π}{4}) - sin (π) sin (\frac{π}{4})

cos (\frac{5 π}{4})

Write

cos (\frac{5 π}{4})

cos (π + \frac{π}{4})

= cos (π + \frac{π}{4})

Use the Angle Sum identity:

cos (s + t) = cos (s) cos (t) - sin (s) sin (t)

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

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

Use the following trivial identity:

cos (π) = (- 1)

cos (π)

cos (x)

periodicity table with

2 πn

cycle:

x 0 \frac{π}{6} \frac{π}{4} \frac{π}{3} \frac{π}{2} \frac{2 π}{3} \frac{3 π}{4} \frac{5 π}{6} cos (x) 1 \frac{3}{2} \frac{2}{2} \frac{1}{2} 0 - \frac{1}{2} - \frac{2}{2} - \frac{3}{2} x π \frac{7 π}{6} \frac{5 π}{4} \frac{4 π}{3} \frac{3 π}{2} \frac{5 π}{3} \frac{7 π}{4} \frac{11 π}{6} cos (x) - 1 - \frac{3}{2} - \frac{2}{2} - \frac{1}{2} 0 \frac{1}{2} \frac{2}{2} \frac{3}{2}

= (- 1)

Use the following trivial identity:

cos (\frac{π}{4}) = \frac{2}{2}

cos (\frac{π}{4})

cos (x)

periodicity table with

2 πn

cycle:

x 0 \frac{π}{6} \frac{π}{4} \frac{π}{3} \frac{π}{2} \frac{2 π}{3} \frac{3 π}{4} \frac{5 π}{6} cos (x) 1 \frac{3}{2} \frac{2}{2} \frac{1}{2} 0 - \frac{1}{2} - \frac{2}{2} - \frac{3}{2} x π \frac{7 π}{6} \frac{5 π}{4} \frac{4 π}{3} \frac{3 π}{2} \frac{5 π}{3} \frac{7 π}{4} \frac{11 π}{6} cos (x) - 1 - \frac{3}{2} - \frac{2}{2} - \frac{1}{2} 0 \frac{1}{2} \frac{2}{2} \frac{3}{2}

= \frac{2}{2}

Use the following trivial identity:

sin (π) = 0

sin (π)

sin (x)

periodicity table with

2 πn

cycle:

x 0 \frac{π}{6} \frac{π}{4} \frac{π}{3} \frac{π}{2} \frac{2 π}{3} \frac{3 π}{4} \frac{5 π}{6} sin (x) 0 \frac{1}{2} \frac{2}{2} \frac{3}{2} 1 \frac{3}{2} \frac{2}{2} \frac{1}{2} x π \frac{7 π}{6} \frac{5 π}{4} \frac{4 π}{3} \frac{3 π}{2} \frac{5 π}{3} \frac{7 π}{4} \frac{11 π}{6} sin (x) 0 - \frac{1}{2} - \frac{2}{2} - \frac{3}{2} - 1 - \frac{3}{2} - \frac{2}{2} - \frac{1}{2}

= 0

Use the following trivial identity:

sin (\frac{π}{4}) = \frac{2}{2}

sin (\frac{π}{4})

sin (x)

periodicity table with

2 πn

cycle:

x 0 \frac{π}{6} \frac{π}{4} \frac{π}{3} \frac{π}{2} \frac{2 π}{3} \frac{3 π}{4} \frac{5 π}{6} sin (x) 0 \frac{1}{2} \frac{2}{2} \frac{3}{2} 1 \frac{3}{2} \frac{2}{2} \frac{1}{2} x π \frac{7 π}{6} \frac{5 π}{4} \frac{4 π}{3} \frac{3 π}{2} \frac{5 π}{3} \frac{7 π}{4} \frac{11 π}{6} sin (x) 0 - \frac{1}{2} - \frac{2}{2} - \frac{3}{2} - 1 - \frac{3}{2} - \frac{2}{2} - \frac{1}{2}

= \frac{2}{2}

= (- 1) \frac{2}{2} - 0 \cdot \frac{2}{2}

Simplify

= - \frac{2}{2}

Use the following trivial identity:

sin (\frac{π}{6}) = \frac{1}{2}

sin (\frac{π}{6})

sin (x)

periodicity table with

2 πn

cycle:

x 0 \frac{π}{6} \frac{π}{4} \frac{π}{3} \frac{π}{2} \frac{2 π}{3} \frac{3 π}{4} \frac{5 π}{6} sin (x) 0 \frac{1}{2} \frac{2}{2} \frac{3}{2} 1 \frac{3}{2} \frac{2}{2} \frac{1}{2} x π \frac{7 π}{6} \frac{5 π}{4} \frac{4 π}{3} \frac{3 π}{2} \frac{5 π}{3} \frac{7 π}{4} \frac{11 π}{6} sin (x) 0 - \frac{1}{2} - \frac{2}{2} - \frac{3}{2} - 1 - \frac{3}{2} - \frac{2}{2} - \frac{1}{2}

= \frac{1}{2}

= \frac{2 3}{3} - (- \frac{2}{2}) + \frac{1}{2}

Simplify

\frac{2 3}{3} - (- \frac{2}{2}) + \frac{1}{2} : \frac{4 3 + 3 + 3 2}{6}

\frac{2 3}{3} - (- \frac{2}{2}) + \frac{1}{2}

Apply rule

- (- a) = a

= \frac{2 3}{3} + \frac{2}{2} + \frac{1}{2}

Combine the fractions

\frac{2}{2} + \frac{1}{2} : \frac{2 + 1}{2}

Apply rule

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

= \frac{2 + 1}{2}

= \frac{2 3}{3} + \frac{1 + 2}{2}

Least Common Multiplier of

3, 2 : 6

3, 2

Least Common Multiplier (LCM)

Prime factorization of

3 : 3

3

3

is a prime number, therefore no factorization is possible

= 3

Prime factorization of

2 : 2

2

2

is a prime number, therefore no factorization is possible

= 2

Multiply each factor the greatest number of times it occurs in either

3

2

= 3 \cdot 2

Multiply the numbers:

3 \cdot 2 = 6

= 6

Adjust Fractions based on the LCM

Multiply each numerator by the same amount needed to multiply its

corresponding denominator to turn it into the LCM

6

For

\frac{2 3}{3} :

multiply the denominator and numerator by

2

\frac{2 3}{3} = \frac{2 3 \cdot 2}{3 \cdot 2} = \frac{4 3}{6}

For

\frac{2 + 1}{2} :

multiply the denominator and numerator by

3

\frac{2 + 1}{2} = \frac{( 2 + 1 ) \cdot 3}{2 \cdot 3} = \frac{( 2 + 1 ) \cdot 3}{6}

= \frac{4 3}{6} + \frac{( 2 + 1 ) \cdot 3}{6}

Since the denominators are equal, combine the fractions:

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

= \frac{4 3 + ( 2 + 1 ) \cdot 3}{6}

Factor

43 + (2 + 1) 3 : 3 (4 + (1 + 2) 3)

43 + (2 + 1) \cdot 3

3 = 33

= 43 + (2 + 1) 33

Factor out common term

3

= 3 (4 + (1 + 2) 3)

= \frac{3 ( 4 + ( 1 + 2 ) 3 )}{6}

Factor

6 : 2 \cdot 3

Factor

6 = 2 \cdot 3

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

Cancel

\frac{3 ( 4 + ( 1 + 2 ) 3 )}{2 \cdot 3} : \frac{4 + ( 1 + 2 ) 3}{2 3}

\frac{3 ( 4 + ( 1 + 2 ) 3 )}{2 \cdot 3}

Apply radical rule:

3 = 3^{\frac{1}{2}}

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

Apply exponent rule:

\frac{x ^{a}}{x ^{b}} = \frac{1}{x ^{b - a}}

\frac{3 ^{\frac{1}{2}}}{3 ^{1}} = \frac{1}{3 ^{1 - \frac{1}{2}}}

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

Subtract the numbers:

1 - \frac{1}{2} = \frac{1}{2}

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

Apply radical rule:

3^{\frac{1}{2}} = 3

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

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

Rationalize

\frac{4 + 3 ( 1 + 2 )}{2 3} : \frac{4 3 + 3 + 3 2}{6}

\frac{4 + 3 ( 1 + 2 )}{2 3}

Multiply by the conjugate

\frac{3}{3}

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

(4 + (1 + 2) 3) 3 = 43 + 3 + 32

(4 + (1 + 2) 3) 3

= 3 (4 + 3 (1 + 2))

Expand

3 (4 + (1 + 2) 3) : 43 + 3 (1 + 2)

3 (4 + (1 + 2) 3)

Apply the distributive law:

a (b + c) = ab + a c

a = 3, b = 4, c = (1 + 2) 3

= 3 \cdot 4 + 3 (1 + 2) 3

= 43 + 33 (1 + 2)

Apply radical rule:

a a = a

33 = 3

= 43 + 3 (1 + 2)

= 43 + 3 (1 + 2)

Expand

3 (1 + 2) : 3 + 32

3 (1 + 2)

Apply the distributive law:

a (b + c) = ab + a c

a = 3, b = 1, c = 2

= 3 \cdot 1 + 32

Multiply the numbers:

3 \cdot 1 = 3

= 3 + 32

= 43 + 3 + 32

233 = 6

233

Apply radical rule:

a a = a

33 = 3

= 2 \cdot 3

Multiply the numbers:

2 \cdot 3 = 6

= 6

= \frac{4 3 + 3 + 3 2}{6}

= \frac{4 3 + 3 + 3 2}{6}

= \frac{4 3 + 3 + 3 2}{6}

Popular Examples

sin(arccos(-9/(sqrt(145))))

Frequently Asked Questions (FAQ)

What is the value of csc((2pi)/3)-cos((5pi)/4)+sin(pi/6) ?
The value of csc((2pi)/3)-cos((5pi)/4)+sin(pi/6) is (4sqrt(3)+3+3sqrt(2))/6