In order to find the equivalent expression to cos 25°, we can use the following property:
[tex]\cos (x)=\sin (90\degree-x)[/tex]So, for x = 25°, we have:
[tex]\begin{gathered} \cos (25\degree)=\sin (90\degree-25\degree) \\ \cos (25\degree)=\sin (65\degree) \end{gathered}[/tex]Therefore the correct option is the fourth one.
