Given the function f (x) = x ^ 2-cosx, for any x1, X2 on [- π / 2, π / 2], we have the following conditions: A.x1>x2 B.x1^2>x2^2 C.|x1|>x2 The condition that f (x1) > F (x2) is constant is B. why

Given the function f (x) = x ^ 2-cosx, for any x1, X2 on [- π / 2, π / 2], we have the following conditions: A.x1>x2 B.x1^2>x2^2 C.|x1|>x2 The condition that f (x1) > F (x2) is constant is B. why


F (x) = x ^ 2-cosx is an even function on [- π / 2, π / 2] and decreases on [- π / 2,0] and increases on [0, π / 2]. So f (x) = x ^ 2-cosx decreases on [0, π / 2] by the symmetry of the even function



The range of function f (x) = LG (x2 + 8) is
The decreasing interval of the function y = Log1 / 2 ^ (x ^ 2-3x + 2) is
Y = log2x / 4log2x, X belongs to the range of [1 / 2,4]
The decreasing interval of y = log3 (x2 + 6x + 10) is
What are the answers


1. The range of y = LG (x ^ 2 + 8) is [3lg2, + ∞)
2. The decreasing interval of y = Log1 / 2 (x ^ 2-3x + 2) is (1, + ∞)
3. (the function is not very clear)
4. The decreasing interval of y = log3 (x ^ 2 + 6x + 10) is (- ∞, - 3]



If f (x) = [LG (10 ^ x + 1) + ax] (1 + 2 / 2 ^ x-1) is an odd function, then a is equal to
If f (x) = [LG (10 ^ x + 1) + ax] [1 + 2 / (2 ^ x-1)] is an odd function, then a is equal to?
A.0 B.1 C.1/2 D.-1/2


Let g (x) = LG (10 ^ x + 1) + AXH (x) = 1 + 2 / (2 ^ x-1) = (2 ^ X-1 + 2) / (2 ^ x-1) = (2 ^ x + 1) / (2 ^ x-1) H (- x) = [2 ^ (- x) + 1] / [2 ^ (- x) - 1] = (1 + 2 ^ x) / (1-2 ^ x) = - H (x) know h (x) odd function f (x) = g (x) * H (x) f (- x) = g (- x) * H (- x) = - G (- x) * H (x) get g (x) = g (- x) from F (x) = - f (- x)