x Turn on thread page Beta
 You are Here: Home >< Maths

# trig mk7 watch

1. -180°≤x≤180°

sin²(x+10)=0.8
sin(x+10)=√0.8
x+10=63.4 and 117
x=53.4 and 107

where are the other answers?
2. (Original post by thefatone)
-180°≤x≤180°

sin²(x+10)=0.8
sin(x+10)=√0.8
x+10=63.4 and 117
x=53.4 and 107

where are the other answers?
square-rooting 0.8 gives +√0.8 and -√0.8 hence two more values
3. (Original post by TheSammy2010)
square-rooting 0.8 gives +√0.8 and -√0.8 hence two more values
God dam everytime it's something.....
Spoiler:
Show
Thanks a bunch for helping
4. (Original post by TheSammy2010)
square-rooting 0.8 gives +√0.8 and -√0.8 hence two more values
(Original post by thefatone)
-180°≤x≤180°

sin²(x+10)=0.8
sin(x+10)=√0.8
x+10=63.4 and 117
x=53.4 and 107

where are the other answers?
square rooting only gives one answer ... solving the equation correctly gives two.
5. (Original post by TeeEm)
square rooting only gives one answer ... solving the equation correctly gives two.
the back of the textbook say i should have 4 answers o.o
6. (Original post by TeeEm)
square rooting only gives one answer ... solving the equation correctly gives two.
If what you are saying is true, let me pose this question to you.

What's √4

If you say 2 and only 2, you have neglected negatives in the sense that -2 x -2 also equals 4.

So back to the original question, there are 4 roots given the interval.
7. (Original post by thefatone)
the back of the textbook say i should have 4 answers o.o
the reference is on the outcome of the eqaution sin2 (x+10) =0.8
8. (Original post by TheSammy2010)
If what you are saying is true, let me pose this question to you.

What's √4

If you say 2 and only 2, you have neglected negatives in the sense that -2 x -2 also equals 4.

So back to the original question, there are 4 roots given the interval.
you are posing me a question of that magnitude ?
well it is time for me to emigrate ...
9. (Original post by TeeEm)
the reference is on the outcome of the eqaution sin2 (x+10) =0.8
So? You will still get 4 answers?

Are you an A level student?
10. (Original post by TheSammy2010)
So? You will still get 4 answers?

Are you an A level student?
It looks that as from tonight I have reached GCSE ...
11. (Original post by TeeEm)
It looks that as from tonight I have reached GCSE ...
Haha, no worries. You did have me questioning my math skills for a bit XD
12. (Original post by TheSammy2010)
Haha, no worries. You did have me questioning my math skills for a bit XD
Your skills are not in question ... (at least for the time being ...)
your reasoning is ... since your post 6 is wrong but it is all good by me!!
13. To summarise, sqrt(a) is always positive (assuming a>=0). But hence a^2=x ->a=+/-sqrt(x).
14. (Original post by TeeEm)
Your skills are not in question ... (at least for the time being ...)
your reasoning is ... since your post 6 is wrong but it is all good by me!!
Haha yeah, true, now that I look back at it.
15. (Original post by TheSammy2010)
If what you are saying is true, let me pose this question to you.

What's √4

If you say 2 and only 2, you have neglected negatives in the sense that -2 x -2 also equals 4.
That's wrong. and only 2. We define the map over .
16. (Original post by Zacken)
That's wrong. and only 2. We define the map over .
My text book never told me that. I'm only an A level student. I didn't even know what your comment means.
17. (Original post by TheSammy2010)
My text book never told me that. I'm only an A level student. I didn't even know what your comment means.
As am I. Basically: is a function that takes in positive x and outputs only positive y.

Turn on thread page Beta
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: February 20, 2016
Today on TSR

### Been caught plagiarising...

...for the 2nd time this year

### Mum says she'll curse me if I don't go to uni

Discussions on TSR

• Latest
Poll
Useful resources

## Make your revision easier

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams

Can you help? Study help unanswered threads

## Groups associated with this forum:

View associated groups
Discussions on TSR

• Latest

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE