Question

Задачка на 15 баллов, срочно​

Answer 1

$cosa=0,6\ \ \ ,\ \ \ \dfrac{3\pi }{2}<a<2\pi \\\\1+tg^2a=\dfrac{1}{cos^2a}\ \ \ \to \ \ \ \ tga=\pm \sqrt{\dfrac{1}{cos^2a}-1}\\\\\dfrac{3\pi }{2}<a<2\pi \ \ \ \to \ \ \ tga<0\ \ \to \ \ tga=-\sqrt{\dfrac{1}{0,36}-1}=-\sqrt{\dfrac{100}{36}-1}=\\\\\\=-\sqrt{\dfrac{64}{36}}=-\dfrac{8}{6}=-\dfrac{4}{3}\\\\\\\boxed{\; tga=-\dfrac{4}{3}; }$