Consider the function, f(x)=(a+1)−∣x∣a−∣x∣,(a>0) So, f(x)≤0,∀x∈ domain of f(x) Let, (a+1)−∣x∣a−∣x∣=y Then, a−∣x∣=y(a+1)−y∣x∣(y−1)∣x∣=y(a+1)−a∣x∣=y−1y(a+1)≤0,∀x∈ domain of f(x) This implies, y∈(−∞,a+1a)∪(1,∞) So, range of function is, f(x)=y∈[0,a+1a]∪(1,∞)