What is the square of rational number 2?

What is the square of rational number 2?

It can be expressed as: 2 ^ 2

lim x→0,[√(x^2+ x+ 1)-1]/tan2x

Let f (x) = √ (x ^ 2 + X + 1) - 1. G (x) = tan2x
lim[f(x)/x]
=lim{[f(x)-f(0)]/(x-0)}
=f'(0)
=1/2
lim[g(x)/x]
=lim{[g(x)-g(0)]/(x-0)}
=g'(0)
=2
The original formula = Lim [f (x) / x] / Lim [g (x) / x] = 1 / 4

Given X & sup2; + 4Y & sup2; + 8x-4y + 17 = 0, find 2x + 16y =?

The formula is (x + 4) & sup2; + (2y-1) & sup2; = 0, which is x = - 4, y = 1 / 2, 2x + 16y = 0!

Absolute elevation - relative elevation?

Relative elevation: refers to the height of each part of the building. Elevation is divided into relative elevation and absolute elevation. Relative elevation is the zero point of the relative elevation, which is used to mark the elevation of the building construction drawing

It is proved that when n → positive infinity, a ^ n / N! → 0

Let a (n) = a ^ n / N, then a (n + 1) = a ^ (n + 1) / (n + 1)!, a (n + 1) / (n + 1) = A / (n + 1) obviously, starting from a certain term, a (n + 1) / (n + 1) < 1, that is, starting from a certain term, is decreasing

How to solve the equation (x-45) * 60% = 45 + (x-45) * 40%

（X-45）*60% =45 + （X-45）*40%
0.6（x-45)=45+0.4(x-45)
0.6x-0.6×45=45+0.4x-0.4×45
0.2x=45+27-18
x=270

The sum of eight unit fractions is equal to 1. Five of them are 1 / 3, 1 / 6, 1 / 10, 1 / 15 and 1 / 21. What are the other three unit fractions

The factors in the denominator are 2, 3, 5 and 7, and the least common divisor is 210
Taking 210 as the denominator, the sum of the above molecules is 70 + 35 + 21 + 14 + 10 = 150
That is, the sum is 150 / 210, and the remaining three sum up to 60 / 210, that is, 2 / 7
So the remaining three unit fractions are 1 / 7 and two are 1 / 14

By using the property of equivalent infinitesimal, we calculate Tan (2x ^ 2) / 1-cosx when LIM (x → 0)

(tan2x)^2=sin2x/cos2x=4sin(x/2)cos(x/2)cosx/cos2x
1-cosx=2[sin(x/2)]^2
(tan2x)^2/(1-cosx)=2cos(x/2)cosx/[cos2xsin(x/2)]=[cos(3x/2)+cos(x/2)]/[cos2xsin(x/2)]
lim(x→0)(tan2x)^2/(1-cosx)=lim(x→0) [cos(3x/2)+cos(x/2)]/[cos2xsin(x/2)]
(x→0),sin(x/2)→0,cos3x/2 →1 cosx/2 →1
lim(x→0)(tan2x)^/(1-cosx)=∞

There are 51 students in a class. 34% of the boys are equal to 23% of the girls?

Suppose there are x boys, then there are 51-x girls. According to the meaning of the question, we can get the equation: & nbsp; 34x = 23 (51-x), & nbsp; 34x = 34-23x, 1712x = 34, & nbsp; X = 24, then there are 51-24 = 27 girls. A: there are 24 boys and 27 girls in this class

What's six plus twelve is 13 out of 24?
What's four and eight is 13 out of 24?

You can make their denominators the same
13 divided by (4 + 2) = 6 / 13
13 divided by (6 + 3) = 9 / 13
If it's an integer, there's no answer to both