Are you allowed to use Calculus?I'm currently partaking a distance learning course in A-level mathematics, and have reached chapter 4 in Pure Core Maths 1&2. Found everything pretty straight-forward so far, yet this question I would greatly appreciate help with.

Express 3x² - 12x + 5 in the form A(x - B)² - C :

From the first part of the question I have : 3(x - 2)² -7

I'm then asked to find the minimum value of each of the following expressions:

1. 3x² - 12x + 5 = -7 (The value of x obviously being 2).

And 2. (3x² - 12x +5)²

It's part 2 that's confusing me? Really unsure of where to start.