Question

Найти sin a, если cos a=1/7( дробь)​

Answer 1

Відповідь:

$cos a = \frac{1}{7} = \frac{b}{c} ;\\b = 1;\\c = 7;\\sin a = \frac{a}{c} = \frac{\sqrt{c^{2} - b^{2} } }{c} = \frac{\sqrt{49 - 1}}{7} = \frac{\sqrt{48} }{7} =\frac{4 \sqrt{3} }{7}$

cos a = \frac{1}{7}  = \frac{b}{c} ;\\b = 1;\\c = 7;\\sin a = \frac{a}{c} = \frac{\sqrt{c^{2} - b^{2}  } }{c} = \frac{\sqrt{49 - 1}}{7} = \frac{\sqrt{48} }{7}  =\frac{4 \sqrt{3} }{7}\\