<PRE><B>Question 1150697</B>
a)  use the power rule
dz/dx = 6x +12x^2
:
b) f(x) = (x^2+1)(x-5)/x = (x^3 -5x^2 +x -5)/x = x^2 -5x +1 -5/x
:
the last algebra step is the result of distributing x through the expression in parenthesis
:
f&#39;(x) = 2x -5 +5/x^2
:
Note derivative of -5/x use the quotient rule, that is, derivative of -5/x = 0 -(-5)(1)/x^2 = 5/x^2
:
 
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