# Need help with Sine Rule

Watch
#1
So I am doing a trig question that ended up with 11/Sin100 = 8/SinX, I don't know where to go from here. I'm grateful for any help.
0
1 week ago
#2
If you could post a picture of the full question with your working up to then, then we can see where to go from there.
0
1 week ago
#3
I'll be happy to help, is this the alevel or as content?
0
1 week ago
#4
Pretty sure you made a mistake
When working out angle it is not a/sin A = b/sinB
It is the other way around so sinA / a = sinB / b

So in your case: sinX / 8 = sin100 / 11

So you get sinX / 8 = ans
So sinX = ans * 8
So sinX = 0.7162238204
But when it is angles you need to do inverse sin
So you get
Sin^-1 (0.7162238204) = 45.74358566

So the angle is 45 or 46 degrees depending on question

Hope this helps.
Bored gcse maths student.
0
1 week ago
#5
(Original post by Mustafa2021)
Pretty sure you made a mistake
When working out angle it is not a/sin A = b/sinB
It is the other way around so sinA / a = sinB / b
These are equivalent statements
It does not matter which way this relation is written.
1
X

new posts
Back
to top
Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

see more

### See more of what you like onThe Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

### Poll

Join the discussion

#### With no certainty that exams next year will take place, how does this make you feel?

More motivated (65)
27.78%
Less motivated (169)
72.22%