Question

Найдитe tga, если cosa= 15/17, 0<a<пи/2

Answer 1

$tga=? \ cosa= frac{15}{17} \ 0leq a leq frac{ pi }{2} \ \ \ tga= frac{sina}{cosa} \ sina= sqrt{1-( frac{15^{2}}{17^{2}})}= sqrt{1- frac{225}{289}}= sqrt{ frac{64}{289}}= frac{8}{17} \ tga= frac{ frac{8}{17}}{ frac{15}{17}}= frac{8}{17}* frac{17}{15}= frac{8}{15}$

Ответ: tga=8/15