Răspuns :
Aplicam: (sin x)^2 +(cos x)^2 =1
(sin x)^2 =1- (cos x)^2
(sin x)^2 =1- (5/13)^2
(sin x)^2 =1- (25/169)
(sin x)^2 =(169-25)/169
(sin x)^2=144/169
sin x =12/13, cu conditia din enunt: x apartine (0,90) grade.
(sin x)^2 =1- (cos x)^2
(sin x)^2 =1- (5/13)^2
(sin x)^2 =1- (25/169)
(sin x)^2 =(169-25)/169
(sin x)^2=144/169
sin x =12/13, cu conditia din enunt: x apartine (0,90) grade.
[tex]sinx= \sqrt{1-cos^2x}= \sqrt{1-( \frac{5}{13})^2 } = \frac{12}{13} [/tex]
