Posted by Sanya on Tuesday, November 6, 2012 at 10:31am.
I need to find the second derivative for this:
I understand all the steps but for some reason I get the wrong numerator. I get
The answer is -8/9y^3
- AP Calc - Reiny, Tuesday, November 6, 2012 at 11:00am
You did just fine and your second derivative is correct, if you meant (6y^2 - 4x^2)/(9y^3)
except they took it a bit further.
notice your numerator is
-4x^2 + 6y^2
from the original
2x^2 - 3y^2 = 4 , then
4x^2 - 6y^2 = 8 , and
-4x^2 + 6y^2 = -8
to get their -8/9y^3
If you were marked "wrong", then that is bad,
when differentiating implicitly, there are often multiple variations of the same answer.
Here is a way to check if two possible answers are equivalent:
Pick any point which satisfies the original equation, sub that point into the two variations of the derivatives, you should get the same answer if they are equivalent.
the point (√8,2) is on the original curve
y'' -- your answer -- = (24 - 32)/72 = -8/72 = -1/9
y'' -- their answer = -8/72 = -1/9
ok, then !!
Answer This Question
More Related Questions
- AP Calc - I need to find the second derivative for this: 2x^2-3y^2=4 I ...
- Calc I - if f(t)=sqrt(4t+1) find f''(2) I got the first derivative to be: 1/2(4t...
- Simplfing Fractions - Three problems I need to know if I am correct or not if ...
- Calc - sinx+x^2y=1 use implicit differentiation to find the second derivative. ...
- CALC 1 - Suppose that h is a function with h'(x) = xe^x. Find all intervals ...
- Calc I - Find the range of y = (3x-1)/(2x^2 + x - 6) I was going to take the ...
- Calculus - I need help with finding first and second derivative--simplify your ...
- calc - derivative of (x^3/6)+(1/2x)? i got (x^2/2)-(1/2x^2) is that correct? and...
- College Calculus 1 - We have to find the first and second derivative of f(x)=x^(...
- Derivatives - Can you help me find the derivative of these problems...Every ...