With reference to the image above: I solved the quadratic equation and got the 2 values of x as -1 & 5 (as Greg did). Now my understanding is that x can be either -1 or 5 (not the values between them). So I substituted both those values in the equation and got B either way. However, Greg mentioned that value of y will be maximum when we take x=2, which perplexed me. Can we even take x = 2 when we already have x = -1 or 5?
What do you think you did when you “solved the quadratic equation”?
Incorrectly assumed y as 0?
Indeed.