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Advanced MathEasyGraph that never meets the x-axis

Advanced Math practice question

Which of the following equations has a graph in the xy-plane that never crosses or touches the x-axis?

  1. A. y = 2ˣCorrect
  2. B. y = x²
  3. C. y = x
  4. D. y = x² − 1

Answer: A. y = 2ˣ

2ˣ is always positive, so it never reaches 0.

Why the other answers are wrong

B. y = x²
x² touches the x-axis at the origin.
C. y = x
A line through the origin crosses it.
D. y = x² − 1
x² − 1 crosses at x = 1 and x = −1.

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