Question

Just to clarify, the answer is D right? If not, why?

Answer 1

`\begin{gathered} x^2\ge16 \\ \\ \text{Get the critical points} \\ \sqrt[]{x^2}=\sqrt[]{16} \\ x=\pm4 \\ \\ \text{Check the intervals} \\ x\le-4 \\ \text{if }x=-5 \\ x^2\ge16 \\ 25\ge16 \\ x\le-4\text{ works in the original inequality} \\ \\ -4\le x\le4 \\ x^2\ge16 \\ \text{if }x=0 \\ 0\ge16 \\ -4\le x\le4\text{ does not work} \\ \\ x\ge4 \\ \text{if }x=5 \\ x^2\ge16 \\ 25\ge16 \\ x\ge4\text{ works} \end{gathered}`

The given graph therefore, is the solution of x² ≥ 16.