Question: How to Solve an Integration Problem with Multiple Variables?

soopo
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Homework Statement


Let
F(x) = integral from x to 1 ( 3t^3 - x^2 t ) dt

1. Calculate F'(x)

The Attempt at a Solution



I know the answer is

x^3 + x.

However, I am not sure how it is obtained.

I know about implicit differentian, but I have never done implicit integration.

How can you solve the problem?
 
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In this case, you can simply work out the integral.
Do the t-integration, it will give you
\frac34 t^4 - \frac12 x^2 t^2
evaluated between the boundaries t = x and t = 1.
Then differentiate.
 
CompuChip said:
In this case, you can simply work out the integral.
Do the t-integration, it will give you
\frac34 t^4 - \frac12 x^2 t^2
evaluated between the boundaries t = x and t = 1.
Then differentiate.

Thank you for your answer!

The solution was much easier than I first thought.
 
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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