Math Is Fun Forum

sarsalan

Member

Registered: 2008-11-03

Posts: 16

continuous function

Q:1:- Prove that the function   f(x)=x^3-2x+3  is continuous.

Ricky

Moderator

Registered: 2005-12-04

Posts: 3,791

Re: continuous function

See this thread.

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"In the real world, this would be a problem.  But in mathematics, we can just define a place where this problem doesn't exist.  So we'll go ahead and do that now..."

G_Einstein

Member

Registered: 2008-08-30

Posts: 124

Re: continuous function

A function is countinous when  lim(delta x--->0) delta y=0

f(x)=x^3-2x+3

SO   lim(delta  x--->0) (x+ delta x)^3 -2(x+delta x) +3 -x^3+2x-3=x^3+3[x^2]deltax+3x(delta x)^2 +(delta x)^3 -2x-2delta x +3-x^3+2x-3=3[x^2]deltax+3x(deltax)^2+(deltax)^3-2deltax=0

So this function is countinous

Last edited by G_Einstein (2008-11-12 02:50:36)

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