Explicație pas cu pas:
[tex]E(x) = \sin(x) + \cos\Big( \frac{x}{2} \Big) + \sin\Big( \frac{x}{3} \Big) \\ [/tex]
[tex]E\Big( \frac{\pi}{2} \Big) = \sin\Big( \frac{\pi}{2} \Big) + \cos\Big( \frac{\pi}{4} \Big) + \sin\Big( \frac{x}{6} \Big) = \\ = 1 + \frac{ \sqrt{2} }{2} + \frac{1}{2} = \bf \frac{3 + \sqrt{2} }{2} [/tex]
