The function f (x) = - (x-1) &# 178; + 1, where x belongs to [- 1,2), the range is_____

The function f (x) = - (x-1) &# 178; + 1, where x belongs to [- 1,2), the range is_____

f(x)max=f(1)=1
f(x)min=f(-1)=-3

Find the function range f (x) = x & # 178; - 1, X ∈ [- 1,2]

Solution
f(x)=x²-1
The axis of symmetry is x = 0 and the opening is upward
be
When x = 0, f (x) has the minimum value: F (0) min = - 1
When x = 2, f (x) has the maximum value: F (2) max = 3
The value range is: [- 1.3]

The range of function f (x) = (1-x & # 178;) / (1 + X & # 178;)?

A:
f(x)=(1-x²)/(1+x²)
=(2-1-x²)/(1+x²)
=-1+2/(1+x²)
Because: 1 + X & # 178; > = 1
So: 0