উত্তর সিলেক্ট করলে সঠিক ও ভুল দেখাবে।
ব্যাখ্যা ও সঠিক সমাধান
উত্তর:
6
|a| = √(1² + 2² + 3²) = √(1 + 4 + 9) = √14. The question seems to have a typo in the provided text, but based on the calculation |a| = √(1²+2²+3²) = √14. If the vector was i + 2j + tk, then √(1²+2²+t²) = 7 => 1+4+t² = 49 => t² = 44 => t = √44. Given the options, the provided solution in the image is |a| = √(1²+2²+3²) = √14, but the question text has a typo.