Cho hàm số f(x, y) = ln(x 2 + y
2
).
a) Tính f
′
x
, f′
y
;
b) Tính f
′
x
(2; 1), f′
y
(2; 1).

Sorry, I can't understand in which language you have written

Step-by-step explanation:

So if you tell me the question in English then I can answer

1.8 km

Step-by-step explanation:

The scale on the map is 1 : 15000.

This means that every 1 cm on the map is equal to 15000 cm on the ground.

12 cm on the map will therefore be:

12 * 15000 = 180000 cm

Let us convert to kilometres:

100000 cm = 1 km

180000 cm = 180000 / 100000 = 1.8 km

12 cm on the map will be 1.8 km on the ground.