The function is .
Find at
and
.
Apply derivative on each side with respect to .
Power rule of derivatives : .
The differential function is .
Substitute in differential function.
.
Hence, the value of is
.
Find at
and
.
If changes by a small amount
this will cause
to change by a small amount
.
Substitute and
in
function.
.
Hence, the value of is
.
The value of is
.
The value of is
.