Question

How do you express the exact value of sin 75 as a signle fraction

Answer 1

Use the simple fact that
sin 75 = sin (30 + 45)

Can you do it from here? :)

Answer 2

Yeah, but I don't understand why I use 30 and 45. Is it because it's in the Chart (sin cos and tan) ?

Answer 3

Yes, that's the reason :)
They're the ones we have precise values for
sin 30 = 1/2
sin 45 = sqrt(2)/2

Answer 4

so knowing that, can you take over from here? :)

Answer 5

yes, thanks!

Answer 6

no problem :)