f ( x ) = 3 / √ x
f ( x ) = 3 / x^{1/2}
f ( x ) = 3 * x^{-1/2}
f ´( x ) = 3 * (-1/2)*x^{-1/2-1}
f ´( x ) = -3/2 * x^{-3/2}
kann man so stehen lassen oder auch so schreiben
f ´( x ) = -3/2 / x^{3/2}
f ´( x ) = -3/2 / √ x^3
√ x^3 = √ ( x^2 * x ) = √ x^2 * √ x = x * √ x