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Popular >

-cos((2pi)/3)

Solution

- cos (\frac{2 π}{3})

Solution

\frac{1}{2}

+1

Decimal Notation

0.5

Solution steps

- cos (\frac{2 π}{3})

Use the following trivial identity:

cos (\frac{2 π}{3}) = - \frac{1}{2}

cos (\frac{2 π}{3})

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{1}{2}

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

Simplify

= \frac{1}{2}

Popular Examples

cos (10 π)

cot(arcsin(-2/5))

cot (arcsin (- \frac{2}{5}))

\frac{1}{cos ( 0 )}

arctan (\frac{2}{6})

tan (\frac{- π}{4})

Frequently Asked Questions (FAQ)

What is the value of -cos((2pi)/3) ?
The value of -cos((2pi)/3) is 1/2