you are correct
Next time try to use calculator to prove yourself right
When the question says "without using a calculator", it is only
for showing of working. It does not mean that you cannot use a
calculator to check if you did it correctly.
Thanks for your help! I have one question here, in which my answer
doesn't tally with that of the answer sheet's. However, I think
both are acceptable. Please help me identify the errors, if any,
that I made.
Find all the angles between 0 and 5 which satisfy the
equation
2tan 2x + sq.rt 3 = 0
range : 0<x<5
0<2x<10
tan 2x = - sq.rt 3 / 2
1. 2x is in 2nd or 4th quadrant.
2. tan-1 (sq.rt 3 /2) = 0.7137243789
3. 2x = 2.4278, 5.5694, 8.7110, 11.852(rej)
.: x = 1.21, 2.78, 4.36
the answer from the marking sheet is 1.13 and 2.70.
I did substitute the numbers and values from my answer and that
of the answer sheet's. Both fit into the answer perfectly. I don't
think I missed out on any answers since I did not cancel out
anything. So, I appeal for your help. ;DDDDDDDDDDDDDDDDDDDD