Subject
Bank Exam
Topic
জনতা ব্যাংক পিএলসি [অফিসার (রুরাল ক্রেডিট)] - ১৮.০৭.২০২৫
If (x/y) + (y/x) = √7 then what is the value of (x4/y4) + (y4/x4) ?
If (x/y) + (y/x) = √7 then what is the value of (x4/y4) + (y4/x4) ?
ক)
22খ)
23গ)
25ঘ)
27Explanation
দেওয়া আছে, (x/y) + (y/x) = √7 ∴ x 4 /y 4 + y 4 /x 4 = (x/y) 4 + (y/x) 4 = {(x/y) 2 } 2 + {(y/x) 2 } 2 = {(x/y) 2 + (y/x) 2 } 2 - 2.(x 2 /y 2 ).(y 2 /x 2 ) = {(x/y) 2 + (y/x) 2 } 2 - 2 = [{(x/y) + (y/x)} 2 - 2.(x/y).(y/x)] 2 - 2 = {(√7) 2 - 2} 2 - 2 = (7 - 2) 2 - 2 = 5 2 - 2 = 25 - 2 = 23Related questions
The average of 8 numbers is 8. If 4 is subtracted from each of 6 of these numbers, what is the new average?In the triangle, what is the value of x?'শির নেহারি' আমারি, নতশির ওই শিখর হিমাদ্রির।' এখানে 'নেহারি' শব্দের অর্থ কী?The sum of four consecutive multiples of 4 is 200. What is the largest number?A rectangular field is 3.2 yards long. A fence marking the boundary is 11.2 yards in length. What is the area of the field in square yards?'তমদ্দুন মজলিশ' কে প্রতিষ্ঠা করেন?When the price of each book goes up by Tk. 5, the librarian purchases 20 books less than the required number for Tk. 1200. The original price of the book wasকোন বানানটি প্রমিত নয়?