Question

Which expression is equivalent to cos 25°? cos 65°tan 65°sin 25°sin 65°

Answer 1

In order to find the equivalent expression to cos 25°, we can use the following property:

`\cos (x)=\sin (90\degree-x)`

So, for x = 25°, we have:

`\begin{gathered} \cos (25\degree)=\sin (90\degree-25\degree) \\ \cos (25\degree)=\sin (65\degree) \end{gathered}`

Therefore the correct option is the fourth one.