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# Trig - I'm stuck watch

1. This is not a TeeEm thread - I'm genuinely stuck

The question : AB = AC. Find the value of theta. Ignore the 'b' in the diagram - not relevant to the question.

A teacher gave this question to one of my tutees, probably not realising how hard it is. The best I've done is get to a quartic but I could've made a mistake and I couldn't solve the quartic directly anyway.

Help!

(Please post any solutions in spoilers)
2. no thanks
that is not a fun looking question...

just had a very brief attempt but got scared off pretty quickly xD
3. What study level is this?
4. (Original post by notnek)
This is not a TeeEm thread - I'm genuinely stuck

The question : AB = AC. Find the value of theta.

A teacher gave this question to one of my tutees, probably not realising how hard it is. The best I've done is get to a quartic but I could've made a mistake and I couldn't solve the quartic directly anyway.

Help!
doesn't seem too difficult i'm doing it currently
5. (Original post by thefatone)
doesn't seem too difficult i'm doing it currently
I could just be being stupid.
6. (Original post by notnek)
I could just be being stupid.
oops i made a mistake xD
7. (Original post by surina16)
What study level is this?
The student who was given this question is in Year 13 doing A Level Maths (not further maths).

I have no idea where the teacher got the question from or if they made it themselves.
8. (Original post by notnek)
This is not a TeeEm thread - I'm genuinely stuck

The question : AB = AC. Find the value of theta.

A teacher gave this question to one of my tutees, probably not realising how hard it is. The best I've done is get to a quartic but I could've made a mistake and I couldn't solve the quartic directly anyway.

Help!

(Please post any solutions in spoilers)
Are we solving it in terms of b or is b to be determined somehow?
9. (Original post by morgan8002)
Are we solving it in terms of b or is b to be determined somehow?
Finding it in terms of b would be too easy!

No you're meant to find the theta angle. The 'b' is not relevant to the question.
10. (Original post by notnek)
Finding it in terms of b would be too easy!

No you're meant to find the theta angle. The 'b' is not relevant to the question.
i'm certain i haven't done this right, i don't think i can actually do this............
11. presumably you mean find theta in terms of b

12. (Original post by notnek)
Finding it in terms of b would be too easy!

No you're meant to find the theta angle. The 'b' is not relevant to the question.
I got
Spoiler:
Show
I have no idea if that's right though. I'm attempting to check but it's a mess.

edit: No it was wrong. I have another idea though.
13. (Original post by the bear)
presumably you mean find theta in terms of b

You wish.
14. (Original post by notnek)
The student who was given this question is in Year 13 doing A Level Maths (not further maths).

I have no idea where the teacher got the question from or if they made it themselves.
Explains why I could only get this far with my limited gcse knowledge (which is still wrong)

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15. (Original post by morgan8002)
I got
Spoiler:
Show
I have no idea if that's right though. I'm attempting to check but it's a mess.
just checking how that would fit with the other angles around the triangle suggest that you're right,granted i could've made a mistake checking to see if you made one
16. (Original post by drandy76)
just checking how that would fit with the other angles around the triangle suggest that you're right,granted i could've made a mistake checking to see if you made one
It would fit. 90 is correct
17. (Original post by drandy76)
just checking how that would fit with the other angles around the triangle suggest that you're right,granted i could've made a mistake checking to see if you made one
There's a chance it's correct, but there was a mistake in my working.
18. (Original post by morgan8002)
I got
Spoiler:
Show
I have no idea if that's right though. I'm attempting to check but it's a mess.

edit: No it was wrong. I have another idea though.
Wha?

I just checked using the sine and cosine rules and 90 was fine
19. (Original post by morgan8002)
I got
Spoiler:
Show
I have no idea if that's right though. I'm attempting to check but it's a mess.

edit: No it was wrong. I have another idea though.
M8 me and @student403 already vouched pls dont dis this
20. (Original post by Student403)
Wha?

I just checked using the sine and cosine rules and 90 was fine
I'm pretty confused. My last line of working was , which I wrote down the wrong solution . There was something else that could have been 0 instead which I'm working on now, but I don't see any reason why I would accidentally come up with the right answer.

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