If the function f (x) = ax ^ 4 + BX ^ 2 + C is known and the tangent equation at x = 1 is y = X-2, then the analytic expression of F (x) is given

If the function f (x) = ax ^ 4 + BX ^ 2 + C is known and the tangent equation at x = 1 is y = X-2, then the analytic expression of F (x) is given

The function f (x) = ax ^ 4 + BX ^ 2 + C, 1 = a * 0 + b * 0 + C, C = 1F '(x) = 4ax ^ 3 + 2bxf' (1) = 4A + 2B = 1. (1) when x = 1, f (1) = a + B + C = a + B + 1, then there is a + B + 1 = 1-2, a + B = - 2. (2) (1) - 2 (2): 2A = 5, a = 5 / 2B = - 2-A = - 2-5 / 2 = - 9 / 2, so a = 5 / 2, B = - 9 / 2, C = 1F (x) =