What is the value of cos(-(5pi)/6) ?

The value of cos(-(5pi)/6) is -(sqrt(3))/2

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

Popular >

cos(-(5pi)/6)

cos (- \frac{5 π}{6})

- \frac{3}{2}

Decimal Notation

- 0.86602 \dots

Solution steps

cos (- \frac{5 π}{6})

Use the following property:

cos (- x) = cos (x)

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

= cos (\frac{5 π}{6})

Use the following trivial identity:

cos (\frac{5 π}{6}) = - \frac{3}{2}

cos (\frac{5 π}{6})

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{3}{2}

= - \frac{3}{2}

2 tan^{2} (x) - 2 = 0

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

cos (x) = 5

2 cos (θ) - 3 = 0

tan (π)