Solving for Integral with Partial Differentiation

Economist2008
Messages
5
Reaction score
0
Do you guys know if it's possible to solve for the following integral

l(t)=∫ {a+ [b+cL(t)+exp^L(t)]/d } dt

where a, b, c and d are constants and the derivative of L(t) is l(t).

Thanks in advance!
 
Physics news on Phys.org
If you differentiate both sides, you get a DE of the form:
L'' = f(L).

You have by the chain rule:
d^2 L /dt = (dL/dt) d/dL (dL/dt) and
L'' = L' d/dL (L') = d/dL 1/2 (L')^2 = f(L) which is separable.

EDIT: Why does your thread read "partial differentiation"?
 
Prove $$\int\limits_0^{\sqrt2/4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx = \frac{\pi^2}{8}.$$ Let $$I = \int\limits_0^{\sqrt 2 / 4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx. \tag{1}$$ The representation integral of ##\arcsin## is $$\arcsin u = \int\limits_{0}^{1} \frac{\mathrm dt}{\sqrt{1-t^2}}, \qquad 0 \leqslant u \leqslant 1.$$ Plugging identity above into ##(1)## with ##u...
Back
Top