Proving Integrability of Constant Function f on [a,b]

  • Thread starter Thread starter tomboi03
  • Start date Start date
  • Tags Tags
    Constant Function
tomboi03
Messages
74
Reaction score
0
Suppose that f is integrable on [a,b]. Let c E \Re. Prove that cf is integrable on [a,b] and that
\int cf= c \int f
(both integrals goes from a to b i didn't kno how to put it in the integral)

I'm not sure how to go about this problem
Please help me out~
Thanks
 
Physics news on Phys.org
When you are completely "stuck", look back to the definitions.

How have you defined \int_a^b f(x) dx?
 
okay, i just got a hint saying that it would be best if we treat this separately with the cases c\leq0 and c\geq0.

how would that help me out? wouldn't it just be the same thing except it will be either negative or positive?
 
How have you defined \int_a^b f(x)dx?
 
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