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

# Questions about solving equations with indices watch

1. I somewhat have trouble with getting all indices on one side
so the question is

3/4x to the power of 3 - 6/x = 0

So i took the 6/x to the other side, but now with the powers wouldnt I take the 6/x and multiply x3 by the x on that side to get x4? the answer book gets x down to the power of 3 but I dont know how
2. Can you use brackets to make it clear what you mean 3/4x^3 could mean quite a few things.
3. (Original post by SunDun111)
...
As above, could you provide a picture or make use of brackets to clarify your meaning. What you've written could mean , it could mean it could mean , etc...
4. (Original post by Zacken)
As above, could you provide a picture or make use of brackets to clarify your meaning. What you've written could mean , it could mean it could mean , etc...
Its 3/4 as a number then x3 next to it, basically 0.75x to the power of 3
5. (Original post by SunDun111)
Its 3/4 as a number then x3 next to it, basically 0.75x to the power of 3
Okay, so . First step, as you said, bring the to the other side, this gets us: .

Multiply both sides by :

.

Divide both sides by :

.

Take the fourth root of both sides, see if you can do this yourself:
Spoiler:
Show

Which step don't you understand?
6. (Original post by Zacken)
Okay, so . First step, as you said, bring the to the other side, this gets us: .

Multiply both sides by :

.

Divide both sides by :

.

Take the fourth root of both sides, see if you can do this yourself:
Spoiler:
Show

Which step don't you understand?
Nothing thanks, I knew how to do it and I got what you got but I realised I wasnt getting the right answer because i copied down the wrong equation
7. (Original post by SunDun111)
Nothing thanks, I knew how to do it and I got what you got but I realised I wasnt getting the right answer because i copied down the wrong equation
Ouch, that's good then - you know your understanding and methodology is correct. Well done!
8. (Original post by Zacken)
Ouch, that's good then - you know your understanding and methodology is correct. Well done!
Thanks, quick question when you differentiate something and asked to prove its a decreasing function what do you do?
9. (Original post by SunDun111)
Thanks, quick question when you differentiate something and asked to prove its a decreasing function what do you do?
Remember yesterday I told you that to show a function is increasing, you show it's derivative is always positive? Can you guess what you have to do for decreasing functions?
Spoiler:
Show
Show the derivative is always negative. (i.e: always less than 0).
10. (Original post by Zacken)
Remember yesterday I told you that to show a function is increasing, you show it's derivative is always positive? Can you guess what you have to do for decreasing functions?
Spoiler:
Show
Show the derivative is always negative. (i.e: always less than 0).
too much revision I forget things haha thanks
11. (Original post by SunDun111)
too much revision I forget things haha thanks
Don't worry about it, it's good that you're asking and clearing things up. You're welcome.
12. (Original post by Zacken)
Don't worry about it, it's good that you're asking and clearing things up. You're welcome.
I looks at your posts on Domains and Range's and for some reason I simply struggle to understand it, I really need to learn it as in C3 a lot of topics are linked with it, do you recommend any good videos about it? because i really struggle with it
13. (Original post by SunDun111)
I looks at your posts on Domains and Range's and for some reason I simply struggle to understand it, I really need to learn it as in C3 a lot of topics are linked with it, do you recommend any good videos about it? because i really struggle with it
Which bits do you struggle to understand?

If I told you to find me the domain of what is your thought process?
14. (Original post by Zacken)
Which bits do you struggle to understand?

If I told you to find me the domain of what is your thought process?
I struggle with all of it, in the exercise book the questions are difficult because they ask me to sketch the graph of it which I hate doing because some of the graphs are difficult to draw,
Is it the number for which the calculator displays an error?
15. (Original post by SunDun111)
I struggle with all of it, in the exercise book the questions are difficult because they ask me to sketch the graph of it which I hate doing because some of the graphs are difficult to draw,
Is it the number for which the calculator displays an error?
Yes, whenever you're given a fraction function (called a rational function), the domain will be the set of numbers for which the denominator is not zero.

So in this case, the domain is .

What about the domain of ? What do you know about square roots, what does that mean for their domain?

Get used to graph sketching, it's a very important skill.
16. (Original post by Zacken)
Yes, whenever you're given a fraction function (called a rational function), the domain will be the set of numbers for which the denominator is not zero.

So in this case, the domain is .

What about the domain of ? What do you know about square roots, what does that mean for their domain?

Get used to graph sketching, it's a very important skill.
Would it be 1 because 1-2 is negative square root?
17. (Original post by SunDun111)
Would it be 1 because 1-2 is negative square root?
No, in this case you know that your square root is valid as long as the inside of it is positive or zero, so .

So your domain is . Perhaps you should go over this with a teacher?
18. (Original post by Zacken)
No, in this case you know that your square root is valid as long as the inside of it is positive or zero, so .

So your domain is . Perhaps you should go over this with a teacher?
Yeah I'm going to when I'm back at school on the 11th, but its so long I want to learn it now, just looking for a few videos.
19. (Original post by SunDun111)
Yeah I'm going to when I'm back at school on the 11th, but its so long I want to learn it now, just looking for a few videos.
Video 1

Video 2

Reply
Submit reply
Turn on thread page Beta

### Related university courses

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: April 7, 2016
Today on TSR

### Edexcel C3 Maths Unofficial Markscheme

Find out how you've done here

### 3,196

students online now

Exam discussions

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

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

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.