Really? I haven't learned it yet and I'm in grade 5.
I just finished grade 4, and I don't know sine, cosine, tangent and other stuff. I asked my dad, I didn't quite get it.
Sine and cosine is a long way off from grade 3. That's trigonometry.
Either he's just in some different school or he's lying. I'm still wondering if he meant form 3, which is ninth grade.
Oh. That's what form three is.
He's lying. I posted that before I read some of the other posts.
He has to be lying..
Hope you got that help you needed!
If you have any further questions on CoSine let me know!
Eh that post is so messy...