Consider the maximization model:

F(x₁, x₂, x₃, x₄)=x₁²x₂² +x₃x₄²+a₁x₁ +a₂x₂ -x₃+a₄

subject to x₁+ x₂- a₃x₃+ a₄x₄=0

a) Write out all the first and second-order conditions. (You do not need to solve these conditions.)

b) What does the maximization problem itself tell us about the signs of each of the

following partial derivatives

dx₁/da₁

dx₂/da₂

dx₃/da₃

dx₄/da₄

note: (a) means Alpha.