was the killer. The one that separated the A from the B. The function ( p(x) = x^4 - 8x^2 + 16 ). Find all real roots. Hence solve the inequality ( p(x) < 0 ). She factorised: let ( u = x^2 ). Then ( u^2 - 8u + 16 = (u-4)^2 ). So ( p(x) = (x^2 - 4)^2 = (x-2)^2 (x+2)^2 ).
Elena stared at the clock on the wall of Exam Hall 4. 9:02 AM. She had 58 minutes left. core pure -as year 1- unit test 5 algebra and functions
One down.