Length of a Curve: Find Length from 0 to 2

  • Thread starter Thread starter skateza
  • Start date Start date
  • Tags Tags
    Curve Length
skateza
Messages
45
Reaction score
0

Homework Statement



I need to find the length of \frac{\frac{1}{3}x^{3} + x^{2} + x + 1}{4x+4} from x=0 to x=2 but i can not factor this down to be able to set up the integral, any suggestions, here is the derivative:
\frac{\frac{8}{3}x^{3}+8x^{2}+8x}{16x^{2}+32x+16}
It is possible I might have to factor the derivative rather than the function itself which is why i supplied both.
 
Physics news on Phys.org
I would write this as:
\frac{1}{12} \frac{(x^3+ 3x^2+ 3x+ 1)+ 2}{x+1}=\frac{1}{12}\frac{(x+1)^3+ 2}{x+1}= \frac{1}{12}((x+1)^2+ \frac{2}{x+1})
That looks to me like it will be easier to handle.
 
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