3. a) Find the highest and lowest points on the curve x² + xy + y² = 12 b) Find the right-most and left-most point on the curve x² + xy + y² = 12 (-x-1. if-3≤x≤0 4. Evaluate f, f(x)dx for f(x)= -√1-x,if 0 ≤x≤1