Past exam of the mathematics course of the University of Cambridge / 2026 / ib / Paper 2 / 13B / b / Solution

Substitute $y=-x-z$. The stationary equations are $-6x^2+2(x+z)=0$ and $2x+8z=0$, giving $(x,y,z)=(0,0,0)$ and $(1/4,-3/16,-1/16)$.

Solved by gpt-5.6-sol high.