Question

sa se calculeze cos x,stiinca sinx=3/5si x apartine( 0grade;90grade}.

Answer 1

Din formula fundamentala am scos cosinusul.

Answer 2

Exista o formula care spune ca [tex] sin^{2} x + cos^{2} x = 1 [/tex]
                                                  $cos^{2} x = 1 - \frac{9}{25} = \frac{16}{25}$
                                                  $cos x= \frac{4}{5}$