Question

Здравствуйте, помогите пожалуйста ​

Answer 1

Ответ:

формулы:

$\sin( \alpha ) = \sqrt{1 - { \cos( \alpha ) }^{2} } \\ \cos( \alpha ) = \sqrt{1 - { \sin( \alpha ) }^{2} }$

$1) \sin( \alpha ) = - \sqrt{1 - \frac{21}{25} } = - \sqrt{ \frac{4}{25} } = - \frac{2}{5}$

$2) \cos( \alpha ) = - \sqrt{1 - \frac{15}{16} } = - \sqrt{ \frac{1}{16} } = - \frac{1}{4}$

$3) \sin( \alpha ) = - \sqrt{1 - \frac{4 \times 6}{25} } = - \sqrt{ \frac{1}{25} } = - \frac{1}{5}$

$4) \sin( \alpha ) = \sqrt{ 1 - \frac{91}{100} } = \sqrt{ \frac{9}{100} } = \frac{3}{10} = 0.3$

$5) \cos( \alpha ) = \sqrt{1 - \frac{7}{16} } = \sqrt{ \frac{9}{16} } = \frac{3}{4}$

$6) \cos( \alpha ) = \sqrt{1 - \frac{19}{100} } = \sqrt{ \frac{81}{100} } = \frac{9}{10} = 0.9$

$7) \cos( \alpha ) = - \sqrt{1 - \frac{99}{100} } = - \sqrt{ \frac{1}{100} } = - \frac{1}{10} = - 0.1$

$8) \cos( \alpha ) = - \sqrt{1 - \frac{91}{100} } = - \frac{3}{10} = - 0.3$