I am currently writing on a paper in economics and came up with the following problem I couldn't solve so far.
I would like to differentiate the integral from the following equation with regards to q_i
while ^z_i is implicitly defined by the following equation
The result is supposed to be the following equation, though I do not understand the way to arrive at it.
I would be glad if someone could help me to understand the way to the derivative. Please take into consideration that I have no background in mathematics