Problem: If, in the expression x2−3, x increases or decreases by a positive amount a, the expression changes by an amount:
Answer Choices:
A. ±2ax+a2
B. 2ax±a2
C. ±a2−3
D. (x+a)2−3
E. (x−a)2−3
Solution:
y1​=x2−3
y2​=(x±a)2−3
y2​−y1​=±2ax+a2