csat-suneung 2021 Q25

csat-suneung · South-Korea · csat__math-humanities 3 marks Stationary points and optimisation Count or characterize roots using extremum values

Find the positive value of $k$ such that the curve $y = 4 x ^ { 3 } - 12 x + 7$ and the line $y = k$ intersect at exactly 2 points. [3 points]

Find the positive value of $k$ such that the curve $y = 4 x ^ { 3 } - 12 x + 7$ and the line $y = k$ intersect at exactly 2 points. [3 points]