Moderate# Partial Derivative with Respect to a Parameter

EMETRC-E67PNL

Consider the function:

$$u = \beta_0 + (1/2)\beta_1^2x^2 - \beta_1yx.$$

Find the point, $\beta_1^*$, where the partial derivative of $u$ with respect to $\beta_1$ ($\partial u/\partial \beta_1$) is equal to zero.