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Popular >

3cos(120)

Solution

3 cos (12 0^{\circ})

Solution

- \frac{3}{2}

+1

Decimal Notation

- 1.5

Solution steps

3 cos (12 0^{\circ})

Use the following trivial identity:

cos (12 0^{\circ}) = - \frac{1}{2}

cos (12 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{1}{2}

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

Simplify

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

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

Remove parentheses:

(- a) = - a

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

Multiply fractions:

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

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

Multiply the numbers:

1 \cdot 3 = 3

= - \frac{3}{2}

= - \frac{3}{2}

Popular Examples

arctan (\frac{20}{50})

arctan (- 12)

5 cos (22 5^{\circ})

6 cos (2 (0))

- 7 sin (0)

Frequently Asked Questions (FAQ)

What is the value of 3cos(120) ?
The value of 3cos(120) is -3/2