Solution:
y=
Since we have square root ,So the value under this cannot be negative.
It means 2- ≥ 0 ------------- condition (1)
However at the same time we need to take care that ≥ 0 ------------- condition (2)
So considering both the condition we can say x ≥ 0 and x ≤ 4
Let x=0
y = ⟹ valid number under square root
Let x=1
y = ⟹ valid number under square root
Let x=2
y = ⟹ valid number under square root
Let x=3
y = ⟹ valid number under square root
Let x= 4
y = ⟹ valid number under square root
Now Let x=5
y = ⟹ This gives a negative number under square root
From here(x ≥ 5) each and every value of x will give a negative value under square root
So Domain of function is [0,4]
Comments
The domain means the values of x which are acceptable. Here in the root only non negative values are acceptable. Thus 2-√x is greater than or equal to 0.this means 2 G. E √X. MEANS 4 G.E. X( squaring both sides) then this means x lies between 0 and 4.This is the domain