Question

Помогите решить задание 13 и 14

Answer 1

Ответ:

13.

$\frac{ \cos(18^{\circ} ) \cos(12^{\circ} ) - \sin(12^{\circ} ) \sin(18^{\circ} ) }{2 \sin(15^{\circ} ) \cos(15^{\circ} ) } = \frac{ \cos(18^{\circ} + 12^{\circ} ) }{ \sin(2 \times 15^{\circ} ) } = \\ = \frac{ \cos(30^{\circ} ) }{ \sin(30^{\circ} ) } = ctg(30^{\circ} ) = \sqrt{3}$

14.

$\frac{ log_{2}( \sqrt[5]{27} ) }{ log_{2}(27) } \times {3}^{ log_{5}(5) } = log_{27}( \sqrt[5]{27} ) \times {3}^{1} = \\ = log_{27}( {27}^{ \frac{1}{5} } ) \times 3 = \frac{1}{5} \times 3 = \frac{3}{5} = 0.6$