16Hit1600
Advanced MathHardNumber of intersection points

Advanced Math practice question

How many points do the graphs of y = x² and y = 4x − 4 have in common?

  1. A. Exactly oneCorrect
  2. B. Exactly two
  3. C. None
  4. D. Infinitely many

Answer: A. Exactly one

x² = 4x − 4 gives (x − 2)² = 0: one repeated solution, x = 2. The line is tangent to the parabola at (2, 4).

Why the other answers are wrong

B. Exactly two
Two would need two distinct roots; the discriminant 16 − 16 = 0 gives one.
C. None
(2, 4) is on both.
D. Infinitely many
A line and a parabola can't coincide.

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