Hey,

First of all thanks for the great book:)

I have a question regarding page 156 question 4:

Why is only 1 the right answer and not also 3?Thank you.

Glad you’re enjoying the book! 1 and 3 are both *x*-values where the parabolas intersect, but the question asks for the *least* possible value of *a*. 3 would be the answer if the question asked for the greatest possible value of *a*.