Given that the maximum value of the function y = (AX + b) / √ (X & # 178; + 1) is 4 and the minimum value is - 1, then a=_____ ,b=_____ .

Given that the maximum value of the function y = (AX + b) / √ (X & # 178; + 1) is 4 and the minimum value is - 1, then a=_____ ,b=_____ .

Let y = (AX + b) / (X & # 178; + 1) y (X & # 178; + 1) = ax + B, YX & # 178; - ax + (y-b) = 0, because X has a solution, so the discriminant = (- a) &# 178; - 4Y & # 178; + 4yb > = 0, 4Y & #

If the maximum value of function f (x) = - x2 + B on [- 3, - 1] is 4, then its minimum value is______ ．

∵ the image of function f (x) = - x2 + B is a parabola with the opening downward and the Y axis as the symmetry axis, so the function f (x) = - x2 + B is an increasing function on [- 3, - 1]. When x = - 1, the maximum value of function is - 1 + B = 4, and the solution is b = 5. When x = - 3, the minimum value of function is - 9 + 5 = - 4, so the answer is: - 4