Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ • π ƒ -¹ ² ³ °
You are not logged in.
Post a reply
Topic review (newest first)
Notice his graph does not exist for values of x less than zero.
It would be a saddle point. The slope of the graph is 0 at that point, but it is not a local max or min. For example, x^3 has a saddle point at (0,0).
I can't be sure as you don't remember the function, but it is possibly because you didn't find the second derivative of the function. You see, the first derivative can equal zero indicating a local extrema. However, if the second derivative also equals zero at this point it is undefined. The case may be that the function did not have a real value at zero. This is what some call a discontinuity. There may even be a limit as the function approaches zero, but still have no value at that point. Again, the second derivative test would allow you to make this distinction.