What is the value of cos(-(3pi)/(10)) ?

The value of cos(-(3pi)/(10)) is (sqrt(2)sqrt(5-\sqrt{5)})/4

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

Popular >

cos(-(3pi)/(10))

cos (- \frac{3 π}{10})

\frac{2 5 - 5}{4}

Solution steps

cos (- \frac{3 π}{10})

Use the following property:

cos (- x) = cos (x)

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

= cos (\frac{3 π}{10})

Rewrite using trig identities:

sin (\frac{π}{5})

= sin (\frac{π}{5})

Rewrite using trig identities:

\frac{2 5 - 5}{4}

= \frac{2 5 - 5}{4}

sin (32. 2^{\circ})

\frac{3.1 \cdot 1 0 ^{- 4}}{( 8.96 \cdot 1 0 ^{- 2} ) cos ( 3 0 ^{\circ} )}

arccos^{2} (\frac{2}{2})

π + cos (π)

- 2 tanh (0)

What is the value of cos(-(3pi)/(10)) ?
The value of cos(-(3pi)/(10)) is (sqrt(2)sqrt(5-\sqrt{5)})/4