Question

what is the first step in writing $f(x) = 6x^2 + 5 - 42x$ in vertex form?

• factor 6 out of each term.
• factor 6 out of the first two terms.
• write the function in standard form.
• write the trinomial as a binomial squared.

Explanation:

To write a quadratic function in vertex form, the first step is to have it in standard form (\(f(x)=ax^2 + bx + c\)). The given function \(f(x)=6x^2 + 5 - 42x\) is not in standard form (the terms are not ordered as \(ax^2+bx + c\)). So we need to rearrange it to standard form (\(f(x)=6x^2-42x + 5\)) first. Factoring 6 out of terms or writing as a binomial squared would come after having it in standard form.

Answer:

C. Write the function in standard form.