What is the value of 1/2 cos(150) ?

The value of 1/2 cos(150) is -(sqrt(3))/4

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

Popular >

1/2 cos(150)

\frac{1}{2} cos (15 0^{\circ})

- \frac{3}{4}

Decimal Notation

- 0.43301 \dots

Solution steps

\frac{1}{2} cos (15 0^{\circ})

Use the following trivial identity:

cos (15 0^{\circ}) = - \frac{3}{2}

cos (15 0^{\circ})

cos (x)

periodicity table with

36 0^{\circ} n

cycle:

x 0 3 0^{\circ} 4 5^{\circ} 6 0^{\circ} 9 0^{\circ} 12 0^{\circ} 13 5^{\circ} 15 0^{\circ} cos (x) 1 \frac{3}{2} \frac{2}{2} \frac{1}{2} 0 - \frac{1}{2} - \frac{2}{2} - \frac{3}{2} x 18 0^{\circ} 21 0^{\circ} 22 5^{\circ} 24 0^{\circ} 27 0^{\circ} 30 0^{\circ} 31 5^{\circ} 33 0^{\circ} 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{1}{2} (- \frac{3}{2})

Simplify

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

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

Remove parentheses:

(- a) = - a

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

Multiply fractions:

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

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

Multiply:

1 \cdot 3 = 3

= - \frac{3}{2 \cdot 2}

Multiply the numbers:

2 \cdot 2 = 4

= - \frac{3}{4}

= - \frac{3}{4}

arctan (- \frac{6}{8})

arcsin (1.25)

arcsec (\frac{7}{3})

\frac{( 4.1 ) ^{2} sin ( 2 ) ( 15 )}{9.8}

arctan (\frac{173.21}{- 200})