Function bounded on [a,b] with finite discontinuities is Riemann integrable

natasha d
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Homework Statement



to prove that a function bounded on [a,b] with finite discontinuities is Riemann integrable on [a,b]

Homework Equations



if f is R-integrable on [a,b], then \forall \epsilon > 0 \exists a partition P of [a,b] such that U(P,f)-L(P,f)<\epsilon


The Attempt at a Solution


the term on the LHS must be made <ε
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You're almost there! You can choose your c_j'' and c_j' to be as close as you want, can't you?
 
make it small enough to neglect the second term on the RHS?
 
Thats the idea. You can choose c_j''-c_j' to be less than some multiple of epsilon and then proceed.
 
got it thanks
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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...
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