Question 207055
Sorry, I don't know how to input the delta sign.

x=9 so y=sqrt(9)=3
since x=9, delta_x= 0.9, then x + delta_x=9.9
y + delta_y=sqrt (x + delta_x)= sqrt (9.9)=3.146 (approx.)
---
delta_y=(y + delta_y)-y=3.146-3=0.146
---
so, delta_y/delta_x=0.146/0.9=<u>0.0162</u>
---