1. Найдём сначала \(\displaystyle \sqrt{ 2025}{\small . } \)
\(\displaystyle \sqrt{ 2025} {\small } \)– это такое неотрицательное число, квадрат которого равен \(\displaystyle 2025{\small .}\)
По таблице квадратов находим, что \(\displaystyle 2025=45^2{\small .}\)
| | Е д и н и ц ы |
| \(\displaystyle \bf \color{blue}{0}\) | \(\displaystyle \bf \color{blue}{1}\) | \(\displaystyle \bf \color{blue}{2}\) | \(\displaystyle \bf \color{blue}{3}\) | \(\displaystyle \bf \color{blue}{4}\) | \(\displaystyle \bf \color{blue}{5}\) | \(\displaystyle \bf \color{blue}{6}\) | \(\displaystyle \bf \color{blue}{7}\) | \(\displaystyle \bf \color{blue}{8}\) | \(\displaystyle \bf \color{blue}{9}\) |
Д
е
с
я
т
к
и | \(\displaystyle \bf \color{blue}{1}\) | \(\displaystyle 100\) | \(\displaystyle 121\) | \(\displaystyle 144\) | \(\displaystyle 169\) | \(\displaystyle 196\) | \(\displaystyle 225\) | \(\displaystyle 256\) | \(\displaystyle 289\) | \(\displaystyle 324\) | \(\displaystyle 361\) |
| \(\displaystyle \bf \color{blue}{2}\) | \(\displaystyle 400\) | \(\displaystyle 441\) | \(\displaystyle 484\) | \(\displaystyle 529\) | \(\displaystyle 576\) | \(\displaystyle 625\) | \(\displaystyle 676\) | \(\displaystyle 729\) | \(\displaystyle 784\) | \(\displaystyle 841\) |
| \(\displaystyle \bf \color{blue}{3}\) | \(\displaystyle 900\) | \(\displaystyle 961\) | \(\displaystyle 1024\) | \(\displaystyle 1089\) | \(\displaystyle 1156\) | \(\displaystyle 1225\) | \(\displaystyle 1296\) | \(\displaystyle 1369\) | \(\displaystyle 1444\) | \(\displaystyle 1521\) |
| \(\displaystyle \bf \color{blue}{4}\) | \(\displaystyle 1600\) | \(\displaystyle 1681\) | \(\displaystyle 1764\) | \(\displaystyle 1849\) | \(\displaystyle 1936\) | \(\displaystyle 2025\) | \(\displaystyle 2116\) | \(\displaystyle 2209\) | \(\displaystyle 2304\) | \(\displaystyle 2401\) |
| \(\displaystyle \bf \color{blue}{5}\) | \(\displaystyle 2500\) | \(\displaystyle 2601\) | \(\displaystyle 2704\) | \(\displaystyle 2809\) | \(\displaystyle 2916\) | \(\displaystyle 3025\) | \(\displaystyle 3136\) | \(\displaystyle 3249\) | \(\displaystyle 3364\) | \(\displaystyle 3481\) |
| \(\displaystyle \bf \color{blue}{6}\) | \(\displaystyle 3600\) | \(\displaystyle 3721\) | \(\displaystyle 3844\) | \(\displaystyle 3969\) | \(\displaystyle 4096\) | \(\displaystyle 4225\) | \(\displaystyle 4356\) | \(\displaystyle 4489\) | \(\displaystyle 4624\) | \(\displaystyle 4761\) |
| \(\displaystyle \bf \color{blue}{7}\) | \(\displaystyle 4900\) | \(\displaystyle 5041\) | \(\displaystyle 5184\) | \(\displaystyle 5329\) | \(\displaystyle 5476\) | \(\displaystyle 5625\) | \(\displaystyle 5776\) | \(\displaystyle 5929\) | \(\displaystyle 6084\) | \(\displaystyle 6241\) |
| \(\displaystyle \bf \color{blue}{8}\) | \(\displaystyle 6400\) | \(\displaystyle 6561\) | \(\displaystyle 6724\) | \(\displaystyle 6889\) | \(\displaystyle 7056\) | \(\displaystyle 7225\) | \(\displaystyle 7396\) | \(\displaystyle 7569\) | \(\displaystyle 7744\) | \(\displaystyle 7921\) |
| \(\displaystyle \bf \color{blue}{9}\) | \(\displaystyle 8100\) | \(\displaystyle 8281\) | \(\displaystyle 8464\) | \(\displaystyle 8649\) | \(\displaystyle 8836\) | \(\displaystyle 9025\) | \(\displaystyle 9216\) | \(\displaystyle 9409\) | \(\displaystyle 9604\) | \(\displaystyle 9801\) |
\(\displaystyle \color{Orange} {2025}=\color{Magenta}4\blue5^2{\small .}\)
Тогда
\(\displaystyle \color{blue}{\sqrt{ 2025}=45}{\small . } \)
2. Подставим найденное значение \(\displaystyle \sqrt{ 2025}\) в исходное выражение:
\(\displaystyle \sqrt{4+\color{blue}{\sqrt{ 2025}}}=\sqrt{4+\color{blue}{45}}=\sqrt{49}{\small .} \)
Осталось найти \(\displaystyle \sqrt{ 49}{\small .} \) Это такое неотрицательное число, квадрат которого равен \(\displaystyle 49{\small .}\)
Так как \(\displaystyle 7^2=49{\small,}\) то
\(\displaystyle \sqrt{ 49}=7{\small .}\)
Окончательно имеем:
\(\displaystyle \sqrt{4+{\sqrt{ 2025}}}=\sqrt{{49}}=7{\small .} \)
Ответ: \(\displaystyle 7{\small . } \)