Troubleshooting Calculations for Equations y=vx and dy/dx=v+x*dv/dx

  • Thread starter Thread starter asdf1
  • Start date Start date
  • Tags Tags
    Calculation
Click For Summary
SUMMARY

The discussion centers on the differentiation of the equations y=vx and dy/dx=v+x*dv/dx. The user identifies that differentiating y=vx leads to dy/dx=v+x*dv/dx, while differentiating dv/dx results in a different expression: dv/dx=(1/x)*dy/dx + [-1/(x^2)]y. The user resolves the discrepancy by manipulating the equations to show that x(dv/dx) + v = dy/dx, confirming the equivalence of the two differentiated forms. This clarification highlights the importance of careful differentiation in calculus.

PREREQUISITES
  • Understanding of calculus, specifically differentiation techniques.
  • Familiarity with the concepts of dependent and independent variables.
  • Knowledge of algebraic manipulation and simplification of equations.
  • Experience with differential equations and their applications.
NEXT STEPS
  • Study the application of the product rule in differentiation.
  • Learn about implicit differentiation and its uses in calculus.
  • Explore the method of solving first-order differential equations.
  • Investigate the relationship between dependent and independent variables in mathematical modeling.
USEFUL FOR

Students of calculus, mathematics educators, and anyone involved in solving differential equations or applying calculus in engineering and physics contexts.

asdf1
Messages
734
Reaction score
0
for this equation, y=vx, it's the same as v=y/x
however, if i differenate the 1st equation, dy/dx=v+x*dv/dx
and if i differenate the 2nd equation, dv/dx=(1/x)*dy/dx + [-1/(x^2)]y
but both differenated equations don't seem the same...
does somebody know where my calculuations went wrong?
 
Physics news on Phys.org
dv/dx=(1/x)*dy/dx + [-1/(x^2)]y

becomes x (dv/dx) = dy/dx - y/x, but v = y/x

so x (dv/dx) = dy/dx - v

or

x (dv/dx) + v = dy/dx, which is same as other equation.
 
thank you very much! :)
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 6 ·
Replies
6
Views
12K
Replies
12
Views
3K
  • · Replies 9 ·
Replies
9
Views
3K
Replies
11
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 7 ·
Replies
7
Views
1K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
1
Views
3K