What do we say in English in the classroom

What do we say in English in the classroom

We are in the classroom

We can eat in the restaurant, but not in the classroom

We can eat in the restaurant,but can't eat in the classroom

Don't eat in the classroom

Don't eat in the classroom!

The perimeter of a rectangle is 30cm, which means that the number of length and width is coprime, so the maximum area of the rectangle is ()

Length and width are 7 and 8, the largest area is 56!

If the line y = ax + B (AB ≠ 0) does not pass through the third quadrant, then which quadrant ()
Baidu to the answer is directly from the topic a

If the line y = ax + B (AB ≠ 0) does not pass through the third quadrant, then A0
y=ax^2+bx=-a(x-b/2a)^2+b^2/4a
Vertex (B / 2a, B ^ 2 / 4A), X

How much is a cubic stone? How much is a cubic sand?

The density of stone is about 1500-1800 kg, and that of sand is about 1300-1600 kg. The density of stone is related to material, and that of sand is related to water content

A polynomial of degree 1 is called a polynomial_______

A polynomial of degree one is called a polynomial of degree one

How to find e (XY) in the covariance formula cov (x, y) = e (((x-e (x)) (y-e (y))) that is cov (x, y) = e (XY) - E (x) e (y)?
X, y are not independent of each other! I don't understand this knowledge point. I'm going to speak on stage tomorrow. Please help me!!

. you need to know the joint distribution of random variables {x, y}, such as a probability measure, mu (x, y)
Then E (XY) = - int, XY, D, mu (x, y)

Calculation unit conversion table
For example: square centimeter = 100 square millimeter, and unit symbol

Length 1 km (km) = 2 City mile = 0.621 mile = 0.540 nautical mile 1 meter = 3 city foot = 3.281 foot 1 city mile = 0.5 km = 0.311 mile = 0.270 nautical mile 1 city foot = 0.333 meter = 1.094 foot 1 mile = 1.609 km = 3.218 City mile = 0.869 nautical mile 1 foot = 0.305 meter = 0.914 City foot 1 inch = 2

What can a and B represent in the formula A & # 178; + 2Ab + B & # 178; = (a + b) & # 178;, a & # 178; - 2Ab + B & # 178; = (a-b) & # 178?

a. B can represent any quantity
For example: a = 3, B = - 4
a=x+2y,b=2x-y
wait.