Step-by-step explanation:
ang hirap naman ng pinasasagot mo

has gradient

which at the point (-1, 4, 3) has a value of

I'm not sure what the given direction vector is supposed to be, but my best guess is that it's intended to say
, in which case we have

Then the derivative of
at (-1, 4, 3) in the direction of
is

Answer:
Circumference ≈ 82.9
Step-by-step explanation:
The formula for calculating the circumference of a circle is:
C = 2πr
Where 3.14 is pi (as stated on your screen)
And r is the radius.
Knowing this substitute those values
C = 2(3.14)(13.2)
Multiply 2 and 3.14.
C = (6.28)(13.2)
Multiply 6.28 and 13.2.
C = 82.9 when rounded.