What is the value of cos((2pi)/(15))cos(pi/(30))-sin((2pi)/(15))sin(pi/(30)) ?

The value of cos((2pi)/(15))cos(pi/(30))-sin((2pi)/(15))sin(pi/(30)) is (sqrt(3))/2

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cos((2pi)/(15))cos(pi/(30))-sin((2pi)/(15))sin(pi/(30))

cos (\frac{2 π}{15}) cos (\frac{π}{30}) - sin (\frac{2 π}{15}) sin (\frac{π}{30})

\frac{3}{2}

Solution steps

cos (\frac{2 π}{15}) cos (\frac{π}{30}) - sin (\frac{2 π}{15}) sin (\frac{π}{30})

Rewrite using trig identities:

cos (\frac{π}{6})

= cos (\frac{π}{6})

Use the following trivial identity:

cos (\frac{π}{6}) = \frac{3}{2}

= \frac{3}{2}

\frac{28}{tan ( \frac{7 π}{18} )}

\frac{120 sin ( 8 )}{30}

arcsin (\frac{( 2 \cdot 5.8 \cdot 1 0 ^{- 7} )}{5.3 \cdot 1 0 ^{- 4}})

cos (65. 7^{\circ})

120 (tan (32. 3^{\circ}))

What is the value of cos((2pi)/(15))cos(pi/(30))-sin((2pi)/(15))sin(pi/(30)) ?
The value of cos((2pi)/(15))cos(pi/(30))-sin((2pi)/(15))sin(pi/(30)) is (sqrt(3))/2