Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

Pages: **1**

**im really bored****Member**- Registered: 2005-05-12
- Posts: 76

Find the square root of (3/2)(x-1) + (sqrt(2x^2 - 7x - 4))

its not equal to anything so its all about manipulation, thats about all I can help lol.

Offline

**Zach****Member**- Registered: 2005-03-23
- Posts: 2,075

I don't suppose you could express that in better terms?

Boy let me tell you what:

I bet you didn't know it, but I'm a fiddle player too.

And if you'd care to take a dare, I'll make a bet with you.

Offline

**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,631

This is as far as I can get:

(3/2)(x-1) + sqrt(2x^2 - 7x - 4))

(3/2)(x-1) + sqrt(2x^2 - 8x + x - 4))

(3/2)(x-1) + sqrt(2x(x-4) + x - 4))

(3/2)(x-1) + sqrt((2x+1)(x-4))

(3/2)(x-1) + sqrt(2x+1)*sqrt(x-4) (best I can do)

Try squaring:

[(3/2)(x-1)]^2 + 2 * (3/2)(x-1) * sqrt(2x+1)*sqrt(x-4) + (2x+1)*(x-4)

9/4 * (x-1)^2 + 3 * (x-1) * sqrt(2x+1)*sqrt(x-4) + (2x+1)*(x-4)

Nope, didn't do any good. Ah well ....

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman

Offline

**im really bored****Member**- Registered: 2005-05-12
- Posts: 76

Im not having any better luck with this problem

Offline

**scobbysteve****Member**- Registered: 2005-05-17
- Posts: 1

i hate maths if hitler was maths, wed all be dead by now

Offline

**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,631

In other words ... Hitler/Maths would have had the power to defeat the Allies, and then would have gone on to kill everyone he now successfully ruled?

This is a new theory I hadn't encountered before.

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman

Offline

**Vulcan****Member**- Registered: 2005-04-23
- Posts: 224

?!?!?!

one day, i couldn't find my hat

then it occured to me that i didn't have one

so i didn't where it!!!

Offline

**im really bored****Member**- Registered: 2005-05-12
- Posts: 76

So does anyone have any idea on how to do this problem?

Offline

**Zach****Member**- Registered: 2005-03-23
- Posts: 2,075

Hitler wasn't going to kill everyone he ruled.

Boy let me tell you what:

I bet you didn't know it, but I'm a fiddle player too.

And if you'd care to take a dare, I'll make a bet with you.

Offline

**complaint****Guest**

Zach got rid of his animal thingy!

**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,631

He did ... I don't know what he replaced it with either.

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman

Offline

**Roraborealis****Member**- Registered: 2005-03-17
- Posts: 1,594

A ferret reaper.

School is practice for the future. Practice makes perfect. But - nobody's perfect, so why practice?

Offline

**stewie****Member**- Registered: 2005-03-28
- Posts: 820

I have 2 admit it looks a lot better - good work zach *throws up*

HAPPY HAPPY, JOY JOY

Fatboy Slim is the band of the 90s, thats if you want to call it a band because its really a one man name

Offline

**Zach****Member**- Registered: 2005-03-23
- Posts: 2,075

Silence yourself, Stewie. My Ferret Reaper will destroy you!

Boy let me tell you what:

I bet you didn't know it, but I'm a fiddle player too.

And if you'd care to take a dare, I'll make a bet with you.

Offline

**im really bored****Member**- Registered: 2005-05-12
- Posts: 76

well anyways back to my original question, I got some help from a friend and they said to start by making the (3/2)(x-1) into one term, and then multiply the sqrt by something that will allow you to combine it with the expanded fraction, then go from there. And they said that the final solution will end up with a square root inside of a square root, and that there wasnt a way that they knew to get around it.

Offline

**Roraborealis****Member**- Registered: 2005-03-17
- Posts: 1,594

Then, we'll first need to multiply out the brackets.

Is that 3/2 a three divided by 2?

School is practice for the future. Practice makes perfect. But - nobody's perfect, so why practice?

Offline

**im really bored****Member**- Registered: 2005-05-12
- Posts: 76

Yes it is a 3 divided by a 2. Now after following some of their advice I combined both terms to make one term which is: (3x - 3) + (sqrt(2x^2 - 7x - 4)) All divided by 2. But I can't get any further at the moment

Offline

**cool_me****Member**- Registered: 2005-05-26
- Posts: 11

hey who ever u r i got the answer for u.telling u something tht go order wise and get ur answer.

the no not possibly will be a perfect sqr. so u can actaually do it calmly!ur answer + question is toooo difficult.

the answer by me is not valid.

NO VALUE.

COZ,

3/2 x -1 + sqrt of (2^2 -7 x -4)

=-3/2 + sqrt of 12

sqrt of 12 does not come in whole nos. u cant add approximation

( if u do it this way)

Offline

**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,631

cool_me, you are genius ...

... I think

Offline

Pages: **1**