Problem: For what value(s) of k does the pair of equations y=x2 and y=3x+k have two identical solutions?
Answer Choices:
A. 94
B. −94
C. 49
D. −49
E. 49 or −49
Solution:
For x2=3x+k to have two equal roots, the discriminant 9+4k must equal zero. ∴k=−49.