Recent content by stat643

thanks

i don't know how to solve it, the sol is "because x is closer to -3 than it is to 1 Hence every x for which x < −1 satisfies the inequality." I am just trying to see why this is the case ... and why x is closer to -3?

| x+3 | < |x-1| The solution states that this inequality implies x is closer to -3 therefore the solution is -1... why?

thanks arildno, very helpful

oh sorry i copied it wrong, it should be (x-1)(x^2+4x-6).. now expanding that get: x^3 + 4x^2 -6x -x^2 -4x + 6 = x^3 + 3x^2 - 10x + 6.. so yeh its right now.. though i still can't get the synthetic devision right (its new to me) i tried to learn it now from...

should i take out the common term x first?

i just looked up synthetic devision on wikipedia and tried it but it didnt work

but how did i get to x^2+4x in the first place?... the original equation was x^3 + 3x^2 - 10x + 6.. i merely copied the solution... so i find the easy root of 1.. then what?

find all roots of x^3 + 3x^2 - 10x + 6 the solution: identify the easy root of x=1, find the remaining roots from (x-1)(x^2+4x) using quadratic formula. The only thing i don't understand here is how to factorize to (x-1)(x^2+4x)... namely the (x^2+4x) part.

oh i see , i just didnt realize n was -1, but obviously it is wen its on the denominator, problem solved. cheers

1/x = x^-1 and yes i can differentiate functions in the form x^n

i can differentiate most other simple functions.. .though can someone please help me to understand why the derivative of f(x)=-5/3x is simply 5/3x^2?

thanks, yeh that is the first identity i learnt, and i didnt even notice it in there lol. thanks for pointing that out.

I copied it correctly so it must of been a typo in the text. It was the only one i couldn't do out of the 5 examples so yeh makes sense now, thanks.

thanks,, i can see that now .