Second Derivative of a Curve: Solving for x | Finding d2y/dx2=0

In summary, to find the value of x for which d^2y/dx^2=0 for the curve with equation y=e^2x-x^2+x-3, you need to solve the equation 4e^2x-2=0. This can be done by using the inverse operation of the exponential function.
  • #1
ibysaiyan
442
0

Homework Statement


A curve has equation y=e^2x-x^2+x-3 , find value of x for which d^2y/dx^2=0.


Homework Equations





The Attempt at a Solution


well. i started by finding out the 1st and 2nd derivative:
y=e^2x-x^2+x-3
dy/dx= 2e2^x-2x+1 and d2y/dx2=4e^2x-2 = 0

dy/dx =>2e^2x=2x-1
=>e^2x = 2x/2 -1/2
e2x= x-1/2 (1)

sub. value (1) into: d2y/dx2.
4e^2x-2= 0
e^2x = 1/2
e^2x = 1/2 (x-1/2)
no idea.. on what to do now =/.
Thanks in adv.
 
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  • #2
ibysaiyan said:
dy/dx =>2e^2x=2x-1
=>e^2x = 2x/2 -1/2
e2x= x-1/2 (1)

I don't know what you did here (why is 2e^2x=2x-1? dy/dx doesn't have to equal 0), but you already got 4e^2x-2 = 0 in the previous step. Just solve for x and you're done.
 
  • #3
How did you go from e^(2x)=1/2, which looks ok, to e^(2x)=(1/2)*(x-1/2) which does not look ok? If it's after 4AM there, I suggest you take a nap.
 
  • #4
Oh k, yea. i can barely hold my eyes lol, alright i guess i will sleep now, thanks for the replies and helping me out :), i will be back tomorrow.Good night for now.
 
  • #5
...
try to use the inverse operation of the exponential
 
Last edited:
  • #6
The policy of the forum is not to present solutions for problems, ok? Just give hints. Never do that again, ok? I'm not going to hit the Report button. But I will next time. ibysaiyan could have gotten this on his own. Don't you see the value in that?
 
Last edited:
  • #7
:[ sorry sorry, i won't do it again
...is it better now ? :D
 
  • #8
nesteel said:
:[ sorry sorry, i won't do it again
...is it better now ? :D

Much better, thanks!
 

What is the concept of finding the second derivative?

The second derivative is a mathematical concept that involves taking the derivative of a function twice. It represents the rate of change of the rate of change of the original function.

Why is finding the second derivative important?

Finding the second derivative is important because it allows us to analyze the curvature of a function. By examining the concavity and inflection points of a function, we can gain a better understanding of its behavior and make predictions about its future behavior.

How do you find the second derivative of a function?

To find the second derivative of a function, you first take the derivative of the function using the appropriate differentiation rules. Then, you take the derivative of the resulting function again. This will give you the second derivative of the original function.

What are some real-world applications of finding the second derivative?

Finding the second derivative has many real-world applications, such as in physics, engineering, and economics. It can be used to analyze the acceleration and curvature of objects, the rate of change of physical systems, and the concavity of economic models.

What is the relationship between the first and second derivative of a function?

The first derivative represents the slope of a function at a given point, while the second derivative represents the rate of change of the slope. In other words, the second derivative tells us how the slope is changing at a specific point on the function.

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