2sinx sin2x

https://www.quora.com/What-is-the-difference-between-2sinx-and-sin2x

Here is one example:

Let α=45∘=π4

Then

2sinα=2sin45∘=2sinπ4=22√2=2√

but,

sin2α=sin2⋅45∘=sin90∘=1

So, 2sinx
means double value of sinx and sin2x means to find the sine function of 2x angle