章 300: Chapter 299: Asking for Help

"Hmm... okay."

He was constantly pressing on Su Ran's spine, and having to control his strength was tiring. Seeing that Su Ran took the initiative, he agreed.

"Listen carefully, elder. The known function f(x) = (1/x) -x. For any x∈(0, k), if f(x)f(k-x)≥[(k/2)-{2/k)] ^2 holds, what is the range of the real number k?"

"..."

Seeing the old man in the black robe pondering hard, Su Ran felt a little embarrassed...

"Ahem, elder, this hand?"

Su Ran pointed at his neck, hinting that he could let go now.

The old man in the black robe paused, finally slowly retracting his hand. Su Ran at last regained his freedom.

"Elder, you shouldn't blame yourself too much. After all, people sometimes forget things as they age; it's normal."

Su Ran rubbed his sore spine, shook his head, and finally felt a little better.