If α and β are roots of x^2 – (4)x + (-12) = 0, find α^2 + β^2.
Note
Use Vieta's formulas instead of solving the quadratic. For x^2 - (4)x + (-12) = 0, the roots α and β satisfy α + β = 4 and αβ = -12. The expression we need is α^2 + β^2. Use the identity α^2 + β^2 = (α + β)^2 - 2αβ. So α^2 + β^2 = (4)^2 - 2(-12) = 16 - (-24) = 40. This is why the correct answer is 40.
