how do I type sin to the second power times 75

I think you want this:

sin²(75) 

We just need to take the sine of 75° and square it.

sin(75) = 0.965925826289

sin²(75) = 0.9330127018920874

And that's it.......

sin(^2*75 = .5 = 1/2

Sin top left squared bottom left.Shows x and a 2 then type 75

The answer is 0.5.