Question

Sin a и ctg a,если cos a = 0.8 и 0

Answer 1

1) cos a=0.8
    sin a=$\sqrt{1-cos^{2} \alpha }$=$\sqrt{1-0.64} = \sqrt{0.36} =0.6$
    ctg a=$\frac{cos \alpha }{sin \alpha } = \frac{0.8}{0.6} = \frac{4}{5} * \frac{5}{3} = \frac{4}{3} =1 \frac{1}{3}$

2)cos a=0
   sin a=$\sqrt{1-0} =1$
   ctg a=$\frac{0}{1} =0$