Vector Algebra

ধর \(\overrightarrow a = 2\widehat i - \widehat j + 5\widehat k\) এবং \(\overrightarrow b = \alpha \widehat i + \beta \widehat j + 2\widehat k\) । যদি \(\left( {\left( {\overrightarrow a \times \overrightarrow b } \right) \times \widehat i} \right).\,\widehat k = {{23} \over 2}\) হয়, তবে \(\left| {\overrightarrow b \times 2\widehat j} \right|\) এর মান হবে