tolong nomor 14 dong

[tex] \frac{1 - \cos(x) }{ \sin(x) } \times \frac{1 + \cos(x) }{1 + \cos(x) } \\ = \frac{1 - ( { \cos(x) }^{2}) }{( { \sin(x) })(1 + \cos(x) )} \\ = \frac{( { \sin(x) }^{2} )}{( \sin(x))(1 + \cos(x) )} \\ = \frac{ \sin(x) }{1 + \cos(x) } [/tex]

ingat sifat identitas
[tex]( { \sin(x) }^{2} ) + ( { \cos(x) }^{2} ) = 1[/tex]

semoga membantu :)