a4-51a2+1 =0 হলে a-1a এর মান কত?
a4-51a2+1 =0 হলে a-1a এর মান কত? Correct Answer ±7
দেওয়া আছে, a4 - 51a1 + 1 = 0⇒a4 + 1 = 51a2⇒a4 + 1a2 = 51a2a2⇒a4a2 + 1a2 = 51.'. a2 + 1a2 = 51এখন, (a - 1a)2 = (a + 1a)2 - 4a1a = a2 + 2a1a + 1a2 - 4 = a2 + 1a2 - 4 + 2 = 51 - 2 = 49.'. a - 1a = 49 = ± 7