Răspuns:
Explicație pas cu pas:
E ( 1/2) = [ (1/2)² - 1] / [ (1/2)² + 1]
-> calculez numaratorul, apoi numitorul, inlocuindu-l pe x cu 1/2
x² - 1 = (1/2)² - 1 = (1/4) - 1 = 1/4 - 4/4 = - 3/4 -> numaratorul
x² + 1 = (1/2)² + 1 = 1/4 + 4/4 = 5/4 -> numitorul fractiei E(1/2)
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E(1/2) = (-3/4)/(5/4) = (-3/4) : (5/4) = (-3/4) × ( 4/5) = - 3/5
E(1/2) = - 3/5
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Il calculez si pe F(1/2) stiind ca F(x) = x/(x²+1)
-> il inlocuiesc pe x cu 1/2
F(1/2) = (1/2) : [(1/2)² + 1) = (1/2) : (1/4+4/4) = (1/2) × (4/5) = 2/5
F(1/2) = 2/5
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b)
E(1/2) + F(1/2) = - 3/5 + 2/5 = - 1/5
