if you are really excellent in calculus please read

[surehands2]

i need help finding the derivative of f(x) = x^-2 i know the answer is

1 over 2x but i need somenoe to help me get it done algebraically? any one?

 

[MattTheSkywalker]

You fucked up.

X^-2

derivative is NOT 1/2x.

it is -2x^-3


unless I am reaqding this wrong.

 

[Warik]

Same way you find derivatives for any other function... subtract 1 from the exponent and multiply.

f(x) = x^-2

-2 - 1 = -3

So the answer is f ' (x) = -2x^-3 = -2/x^3

Who told you it was 1/2x?

-Warik

 

[Warik]

You fucked up.

Damn Matt... what a jerk. =)

-Warik

 

[surehands2]

you guys are right stupid mistake on my hand also can you guys help me with this i have to find the derivatives algebraically of
f(x) = x^-2 then it says find f'(2) can ya help me with the algebra part i wanna make sure i doing it right im stuck at


1/(x+h)^2 - 1/x
______________
h

 

[Warik]

f'(2) just means to plug 2 into the derivative function. You got -2/x^3 as the derivative... so just replace x with 2 and solve.

-Warik

 

[surehands2]

yeah i know that but im also tested on the algerbra part too so i awnna make sure i get it down

 

[surehands2]

by the way im using

f(x+h) - f(x)
__________
h


to find the dervitive

 

[nitlyan]

f(x)=x^-2

with respect to what variable????

 

[surehands2]

dude there is no respect just use
f(x+h) - f(x)
__________
h


that formula when f(X) = X^-2
to find teh derivative

 

[nitlyan]

go to this site surehands

http://school.discovery.com/homeworkhelp/webmath/diff.html


It will show you all of the steps.

 

[FrankRizzo]

God am I glad my degree is hanging on the wall of my office.

 

[Fonz]

by the way im using

f(x+h) - f(x)
__________
h


to find the dervitive

Taking the derrivative using first principles is a
COMPLETE waste of time. You can do it
10X faster by using other rules.

Warik: SLOW-POKE.....Muhahaha!!!!

In math I AM HE-MAN!!!!

Godspeed

 

[Warik]

f(x)=x^-2

with respect to what variable????

With respect to 2.

-Warik