If the real number a B satisfies a + B < 4, then a = 1 and B = 2 find its inverse proposition, no proposition, inverse no proposition, and its true and false

If the real number a B satisfies a + B < 4, then a = 1 and B = 2 find its inverse proposition, no proposition, inverse no proposition, and its true and false

Inverse proposition: if a = 1 and B = 2, then the real numbers a and B satisfy a + B

Write the inverse proposition that the sum of two rational numbers is a rational number

Original proposition: if two numbers are rational, then their sum is rational
Inverse proposition: if the sum of two numbers is rational, then they are both rational
No proposition: if two numbers are not rational, then their sum is not rational
Inverse negative proposition: if the sum of two numbers is not rational, then both numbers are not rational

The sum of the squares of two consecutive positive integers is 841. Find these two numbers

Let these two numbers be x, x + 1, respectively
x²+(x+1)²=841
2x²+2x-840=0
x²+x-420=0
(x+21)(x-20)=0
X = - 21 (rounding off)
Or x = 20
The two numbers are 20 and 21

Find the value range of independent variable x in the following functions: y = x-3 / 2, y = 3 / 4-x, y = 1 / 2x square + 1

X can take all real numbers
If the second question is: y = 3 / (4-x), that is, 4-x is on the denominator, and its value cannot be 0, then x ≠ 4

Simple calculation: 9999 * 23 + 3333 * 31

Original formula = 3333 * 3 * 23 + 3333 * 31
=3333*69+3333*31
=3333*(69+31)
=3333*100
=333300

Formula reasoning of the relationship between displacement and velocity of linear motion with uniform speed change
How to deduce V & sup2; - V0 & sup2; = 2aX? The specific points should be explained,

Initial velocity V0, final velocity v
Acceleration a
t=(v-v0)/a
x=v0*t+1/2at^2
2x=2v0*(v-v0)/a+(v-v0)^2/a
2ax=2v*v0-2v0^2+v^2-2vv0+v0^2
2ax=v^2-v0^2

In the space rectangular coordinate system o-xyz, all the points of Z = 1 constitute a graph______ The distance from point P (2,3,5) to plane xoy is______ ．

Z = 1 means a plane, which is parallel to the xoy plane and has a distance of 1, so the graph formed by all the points of Z = 1 passes through the point (0, 0, 1) and is perpendicular to the Z axis. The distance from the plane P (2, 3, 5) to the plane xoy has nothing to do with its abscissa and ordinate, but only with its vertical coordinate. Since the square of the plane xoy is Z = 0, the distance from the point P (2, 3, 5) to the plane xoy is | 5-0 | = 5, so the answer should be in turn Point (0, 0, 1) and perpendicular to Z axis; 5

When water becomes ice, its volume increases by one tenth. When water becomes ice, its volume decreases?

When water becomes ice, its volume increases by one tenth, and when it becomes water, its volume increases by one eleventh
1/10÷（1+1/10）=1/11

If the number of strands of the rope is n, regardless of the friction force, what is the relationship between the pulling force F and the weight g of the object and the weight g of the moving pulley? What is the relationship between the distance s of the free end movement and the distance h of the species rise?

S=nh
F = [g (object) + G (moving pulley)] n
That's all. Let's give it a point

lne=1,ln1=0
I don't remember
Do you have anything special

Exactly, ln (e ^ 2) = 2 and so on,