There are 7 Replies:
|
|
Message
|
Person and Time
|
|
x^3+y^3=1 y^3=1-x^3 y=1-x (take cube root of both, cube root of 1 makes 1) now getting derivative: y=-1 dunno if it's right, haven't done one like this =P |
|
Nagao
|
Sep 13, 2007
(246 days and 14 hours ago)
|
|
|
o_O I just noticed this when you answed, Nagao . The question at the top of the page says find dy/dx by implicit Differentation. I terms of finding derivative, I think you were right, but because I didn't read the question correctly, you got it wrong (inadvertently). I thank you though: you gave me the idea that you could take the CUBE ROOT of a CUBED term. I think I can use that somewhere in this lesson, though. |
|
Forte Lambardi
|
Sep 13, 2007
(246 days and 12 hours ago)
|
|
|
You wouldn't take the cubic root for a differential. Just use the rules of differentiation, in this case n^x = xn^(x-1), and the 1 of course becomes 0 because it's a constant. dy/dx = y' So for x^3 + y^3 = 1: 3x^2 + 3y^2y' = 0 3y^2y' = -3x^2 y' = -3x^2/3y^2 ...and your end result: y' = -x^2/y^2 |
|
halolegend1
|
Sep 15, 2007
(244 days and 15 hours ago)
|
|
|
If that looked confusing, it's (3y^2)(y') in all occurrences and (-3x^2)/(3y^2) in all occurrences. |
|
halolegend1
|
Sep 15, 2007
(244 days and 15 hours ago)
|
|
|
"You wouldn't take the cubic root for a differential." I never said this. All I said was I could take cubed root for a cubed term which means I may use it for something other than Differentiation. "(-3x^2)/(3y^2) " You can further simplify the expression tion -x^2/y^2 since the 3's will cancel each other. Thanks for the help. I think I see where I went wrong. |
|
Forte Lambardi
|
Sep 16, 2007
(243 days and 18 hours ago)
|
|
|
"You wouldn't take the cubic root for a differential." That was more of a reply to Nagao. "You can further simplify the expression" If you look at my reply again, you will see that I have that answer in bold under "...and your end result:" Glad to help. |
|
halolegend1
|
Sep 17, 2007
(242 days and 15 hours ago)
|
|
|
"That was more of a reply to Nagao." Well, he only did this operation because I misworded the question. I don't blame him, though: it kind of looks like an algebraic problem. |
|
Forte Lambardi
|
Sep 18, 2007
(241 days and 20 hours ago)
|
|