Saved Bookmarks
| 1. |
A positive number is divided into two parts such that the sum of the squares of the two parts is 20. The square of the larger part is 8 times the smaller part. Taking x as the smaller part of the two parts, find the number. |
|
Answer» Let the smaller and larger of two parts be x and y. According to question y2 = 8x Sum of the squares of the two parts is 20. x2 + y2 = 20 x2 + 8x - 20 = 0 x2 - 2x + 10x - 20 = 0 x(x - 2) + 10(x - 2) = 0 (x - 2)(x + 10) = 0 x = 2 or x = -10 (rejected as part of pice never be negative) y2 = 8x y = √8x =√8 x 2 = √16 = 4 Hence, the no. is 2 + 4 = 6 |
|