MHB 15.1.34 Evaluate triple integral

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The triple integral I is evaluated as I = ∫₀^(3π/2) ∫₀^(π) ∫₀^(sin{x}) sin{y} dz dx dy. After integrating with respect to z, the expression simplifies to I = ∫₀^(3π/2) ∫₀^(π) sin(y) sin(x) dx dy. Further integration with respect to x leads to I = ∫₀^(3π/2) sin(y) · 2 dy. The final evaluation yields I = 2, confirming the calculations are correct despite initial confusion with trigonometric functions. The discussion also notes a minor typographical error in the term "integrate."
karush
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15.1.34 Evaluate
$\displaystyle I=\int_{0}^{3\pi/2}\int_{0}^{\pi}\int_{0}^{\sin{x}}
\sin{y} \, dz \, dx \, dy$
integrat dz
$\displaystyle I=\int _0^{3\pi/2}\int _0^{\pi }\sin(y)\sin (x)\, dxdy $
integrat dx
$\displaystyle I=\int _0^{3\pi/2}\sin \left(y\right)\cdot \,2dy$
integrat dy
$I=2$

ok I think its correct, took me an hour to do... trig was confusing
typos mabybe
 
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Show the detail on that dx piece.
 
karush said:
15.1.34 Evaluate
$\displaystyle I=\int_{0}^{3\pi/2}\int_{0}^{\pi}\int_{0}^{\sin{x}}
\sin{y} \, dz \, dx \, dy$
integrat dz
$\displaystyle I=\int _0^{3\pi/2}\int _0^{\pi }\sin(y)\sin (x)\, dxdy $
integrat dx$
This is correct and it can be written
$I=\left(\int_0^{3\pi/2} sin(y)dy\right)\left(\int_0^\pi sin(x)dx\right)$
$= \left[-cos(y)\right]_0^{3\pi/2}\left[-cos(x)\right]_0^\pi= (1)(2)= 2$

By the way, in English, "integrate" has an "e" on the end.

$\displaystyle I=\int _0^{3\pi/2}\sin \left(y\right)\cdot \,2dy$
integrat dy
$I=2$

ok I think its correct, took me an hour to do... trig was confusing
typos mabybe
 
There are probably loads of proofs of this online, but I do not want to cheat. Here is my attempt: Convexity says that $$f(\lambda a + (1-\lambda)b) \leq \lambda f(a) + (1-\lambda) f(b)$$ $$f(b + \lambda(a-b)) \leq f(b) + \lambda (f(a) - f(b))$$ We know from the intermediate value theorem that there exists a ##c \in (b,a)## such that $$\frac{f(a) - f(b)}{a-b} = f'(c).$$ Hence $$f(b + \lambda(a-b)) \leq f(b) + \lambda (a - b) f'(c))$$ $$\frac{f(b + \lambda(a-b)) - f(b)}{\lambda(a-b)}...

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