Answer:
If you've learnt sin(A+B) = sinAcosB + cosAsinB,
sin(4u)
= sin(2u+2u)
= sin(2u)cos(2u) + cos(2u)sin(2u)
= 2 sin(2u) cos(2u).
8/3 = 2 2/3 and -11/3 = -3 2/3
so the middle line is 0 and each big line is 1.
Put the first dot on 2 2/3 or right before the 3rd big line.
Put the second dot on -3 2/3 or the line right after the 4th big line going back from 0
The answer is 3 First you subtract 2 from 17 and then you divide 15 by 5 to get the answer of 3