f(x) = √(a + x^2) = (a + x^2)^{1/2}
Ableiten mit Kettenregel
f'(x) = 1/2·(a + x^2)^{- 1/2}·2·x = x/√(a + x^2)
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f(x) = √(x^2 + 2·a·x + b) = (x^2 + 2·a·x + b)^{1/2}
f'(x) = 1/2·(x^2 + 2·a·x + b)^{- 1/2}·(2·x + 2·a) = (x + a)/√(x^2 + 2·a·x + b)