Question:
My approach for solution: Two possible equations-
- y = x² + 9x + d
- y = -x² -9x + d
For these both i found the highest or lowest point, using: c-(b²/4a)
- d-(81/4)= d-20.25
- d-(81/4)= d-20.25
Then, i used the discriminant to find possible outcomes: b²-4ac
- 81-4(1)(20.25)
- 81-4(-1)(20.25)
Problem Statement:
While I used desmos to just understand why d=20.25 wouldn’t work. However, i still did not completely get it. (btw, the answer is d=-20.25). How would I solve this during the D-day (test day).
Thanks in advance!