Sin (theta / 2 ) = (Sin (theta / 2)) / (cos (theta / 2)) ?

[jonboy]

How is \(\displaystyle \L \;Sin\frac{\theta}{2}\,=\,\frac{Sin\,\frac{\theta}{2}}{cos\,\frac{\theta}{2}}\) ?
What identity?

 

[stapel]

This "identity" isn't. Try plugging some values in, to confirm this, or else compare the graph of sine and tangent.

Eliz.

 

[ChaoticLlama]

you reaaaaaaallly need to review your basic algebra (i.e. division) and functions (i.e. what they are)