Oscar's utility function is u(x)=\left\{\begin{array}{ll}

\sqrt{x} & \text { if } x \geq 0 \\

-\sqrt{-x} & \text { if } x \leq 0

\end{array}\right. Note that is allowed to take on negative values. A positive value is a monetarygain, a negative value is a loss. (a) Is Oscar risk-averse? Explain your answer. Hint: sketch the graph of thefunction u. (b) Consider the lottery L= (0, -10; 1/2,1/2), which yields $0 with probability 1/2 and $10 with probability 1/2. What's the risk premium that Oscar associates with this lottery? How much is he-willing to pay for this lottery?