Math Is Fun Forum

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

You are not logged in.

#1 2009-11-22 18:15:57

Karn
Member
Registered: 2009-11-15
Posts: 14

Number and Algebra

Hello

Solve graphically

(a)         (x+3)(x+2)= 10

(b)        -2x^3 + 3x^2 - 1=4

c)          y= 2x+ 3 and x= 2y + 1


What does it mean to 'solve graphically'

Thank you for any help provided.

Offline

#2 2009-11-22 19:20:49

Anakin
Member
Registered: 2009-10-04
Posts: 145

Re: Number and Algebra

Normally when then the textbook says solve graphically, it means graph it on a graphing calculator or some applet like this: http://www.mathsisfun.com/data/graph.html

And you see for what value of x, y is equal to 0 by looking at the x-intercepts of the graph. That is how you would go about solving it.

Offline

#3 2009-11-22 19:21:54

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Number and Algebra


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Offline

#4 2009-11-22 22:32:16

MathsIsFun
Administrator
Registered: 2005-01-21
Posts: 7,711

Re: Number and Algebra

And you can zoom in to get more accurate values.


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

Offline

#5 2009-11-23 14:28:03

Karn
Member
Registered: 2009-11-15
Posts: 14

Re: Number and Algebra

Thank you

also

How would yous solve b) without a calculator?

Offline

#6 2009-11-23 18:26:17

mmdd1823
Member
Registered: 2009-11-23
Posts: 1

Re: Number and Algebra

Can you give more examples to do with statistics?

Offline

#7 2009-11-23 18:45:34

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Number and Algebra

Hi Karn;

Karn wrote:

How would yous solve b) without a calculator?

Yes:

The school way is possible here:

Factor it:

-( x + 1 ) ( 2x^2 - 5x + 5 ) = - 2x^3 + 3x^2 - 5 = 0

Last edited by bobbym (2009-11-23 18:48:08)


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Offline

#8 2009-11-23 18:57:22

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Number and Algebra

Hi mmdd1823;

Can you give more examples to do with statistics?

No, root location is used when trying to find the roots of equations. Generally statistics is more concerned with the area under curves than with roots.


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Offline

Board footer

Powered by FluxBB