(a)
f(x) = cos(x2)
Innere Ableitung 2x
Äußere Ableitung -sin(x2)
f'(x) = 2x * -sin(x2) = -2x * sin(x2)
Produktregel (uv)' = u'v + uv'
u = 2x | u' = 2
v = -sin(x2) | v' = 2x * -cos(x2)
f''(x) = 2 * (-sin(x2)) + 2x * 2x * -cos(x2) = 2 * (-sin(x2)) + 4x2 * (-cos(x2)) = -2 * sin(x2) - 4x2 * cos(x2)
(b)
f(x) = 1/x = x-1
f'(x) = -x-2 = -1/x2
f''(x) = 2x-3 = 2/x3
Besten Gruß