Problem: The roots of Ax2+Bx+C=0 are r and s. For the roots of x2+px+q=0 to be r2 and s2,p must equal:
Answer Choices:
A. A2B2−4AC​
B. A2B2−2AC​
C. A22AC−B2​
D. B2−2C
E. 2C−B2
Solution:
r+s=−AB​
rs=AC​
r2+2rs+s2= A2B2​2rs=A2C​
r2+s2=A2B2−2AC​
p=−(r2+s2)= A22AC−B2​