∵f(x) is increasing monotonously in the world.
∴2a≤ 1
∴a≤ 1/2
(2) Let x 1∑(0, +∞), then -x∑(-∞, 0).
∴f(-x)=x? [Add to nouns in French etymology ending in -u to form plural]
The function f(x) is an even function on R.
∴f(x)=f(-x)=x? The domain of -x is (0, +∞)
∴f(x)=x? +x,x≤0
x? -x,x≥0
Hope to adopt ~~=v=