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Popular >

42cos(45)

Solution

42 cos (4 5^{\circ})

Solution

212

+1

Decimal Notation

29.69848 \dots

Solution steps

42 cos (4 5^{\circ})

Use the following trivial identity:

cos (4 5^{\circ}) = \frac{2}{2}

cos (4 5^{\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{2}{2}

= 42 \cdot \frac{2}{2}

Simplify

42 \cdot \frac{2}{2} : 212

42 \cdot \frac{2}{2}

Multiply fractions:

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

= \frac{2 \cdot 42}{2}

Divide the numbers:

\frac{42}{2} = 21

= 212

= 212

Popular Examples

arccos(6/(sqrt(86)))

arccos (\frac{6}{86})

sin(60)(sqrt(3))/2

sin (6 0^{\circ}) \frac{3}{2}

- \frac{1}{6} cos^{3} (π)

(sec(120)+cot(225)+cos(315))/(sin(270))

\frac{sec ( 12 0 ^{\circ} ) + cot ( 22 5 ^{\circ} ) + cos ( 31 5 ^{\circ} )}{sin ( 27 0 ^{\circ} )}

arccos (0.174)

Frequently Asked Questions (FAQ)

What is the value of 42cos(45) ?
The value of 42cos(45) is 21sqrt(2)