Answer:
1/8.
Explanation:
Use l'Hopitals rule - we find the derivative of top and bottom of the fraction.
Derivative of the numerator = 0 - 1/2 (16 - x)^-1/2 -1
= 1 / [ 2 * (16 - x)^1/2
Derivative of the denominator = 1
When x approaches 0 this is 1 / (2*4)
= 1/8.
Another way to do this is to multiply top and bottom by 4 + (16 - x)^1/2
This becomes 16 - (16 - x) / x(4 + (16-x)^1/2)
= 1 / (4 + (16 + x)^1/2
When x ---> 0
this = 1 /(4 + 4)
= 1/8.