Let f (x) = (EX-1) (x-1) K (k = 1,2), then () A. When k = 1, f (x) gets a minimum B at x = 1. When k = 1, f (x) gets a maximum C at x = 1. When k = 2, f (x) gets a minimum d at x = 1. When k = 2, f (x) gets a maximum at x = 1

Let f (x) = (EX-1) (x-1) K (k = 1,2), then () A. When k = 1, f (x) gets a minimum B at x = 1. When k = 1, f (x) gets a maximum C at x = 1. When k = 2, f (x) gets a minimum d at x = 1. When k = 2, f (x) gets a maximum at x = 1


When k = 1, the function f (x) = (EX-1) (x-1). The derivative function can obtain f '(x) = ex (x-1) + (EX-1) = (xex-1), f' (1) = E-1 ≠ 0, f '(2) = 2e2-1 ≠ 0, then f (x) can not take the extreme value at x = 1 and x = 2. When k = 2, the function f (x) = (EX-1) (x-1) 2. The derivative function can obtain f' (x) = ex (x-1) 2 + 2 (EX-1) (x-1) = (x-1) (xex + EX-2) When x = 1, f '(x) = 0, and when x > 1, f' (x) > 0, when x0 < x < 1 (x0 is the maximum point), f '(x) < 0, so the function f (x) is an increasing function on (1, + ∞), and a decreasing function on (x0, 1), so the function f (x) gets a minimum on x = 1



The image of the function f (x) = x ^ 3-ax ^ 2 + BX = C is a curve e, and there is a point P on the curve, so that the tangent of e at point P is parallel to the X axis, and the relationship between a and B is obtained
When the derivative f '(x) = 3x ^ 2-2ax + B is obtained, and the slope of derivative function is known to be 0, how to calculate Δ?


Δ = 4A ^ 2-4 * 3 * b = 0 (because there is a unique point P)



Given the function f (x) = x & # 179; + ax & # 178; + B, the tangent of the curve y = f (x) at the point (1,1) is y = X. (1) find the monotone interval of a, B (2) find the monotone interval of F (x), and explain its monotonicity in each interval


(1) If f (x) = ax & # 179; - 3x & # 178; / 2 + B is derived, then f '(x) = 3ax & # 178; - 3x has the tangent equation y = 6x-8 at point (2, f (2)), that is, the slope is k = 6, that is, the derivative function f' (2) = 6, that is, f '(2) = 3A × 2 & # 178; - 3 × 2 = 6, and the solution is a = 1, then f (x) = x & # 179; - 3x &



Given the function FX = ax + 1 / x + B, the tangent of the curve y = FX at point (2,1) is parallel to the x-axis 1. Find the analytic formula of F '(x) 2 for FX


A = quarter B = 0