It is proved that the area of isosceles triangle is the largest among triangles with the same base and equal perimeter Answer by 12 noon tomorrow

Take the middle point of the bottom edge as the origin and the bottom edge as the x-axis to establish a rectangular coordinate system. Because of the same bottom and the same perimeter, that is, the sum of the other two sides is the fixed value, so the triangle is not another point at the two ends of the bottom edge, and the trajectory formed is an ellipse. Because the triangle has the largest area, the distance from the third point to the bottom edge should be the farthest

Verify the correctness of Lagrange mean value theorem for the square of function y = 3x-6x + 1 in the closed interval from 0 to 1

This paper describes Lagrange mean value theorem, and verifies the condition and conclusion of Lagrange mean value theorem of function f (x) = x ^ 2 on [1,2]

For the differentiable function f (x) defined on [a, b], there must be a point C on (a, b) such that f (b) - f (a) = f '(c) (B-A), for your example,
0 exists

The formula of projective theorem in space geometry?

The projective theorem is used to find the angle of two faces
Two planes have intersecting lines. One plane is taken as the datum, and the ratio of the projected area of the other plane in the plane to the original area
It's a dihedral angle

The analytic property of the judgment function f (z) = x ^ 3-3xy ^ 2 + I (3x ^ 2y-y ^ 3)

According to CR equation

If the function f (x) has a second derivative in (a, b), and f (x1) = f (x2) = f (x3), where a

Twice Rolle theorem

The fraction is 295. After adding m to numerator and denominator, the ratio of numerator to denominator is 19:7. What is m?

29 + M5 + M = 197, & nbsp; 19 × (5 + m) = 7 × (29 + m), & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; 95 + 19m = 203 + 7m, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; 12m = 108, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; m = 9

The general solution of the differential equation y '' xlnx = y 'is

y''xlnx=y'
y''/y'=1/(xlnx)=(lnlnx)'
lny'=lnlnx+C1
y'=C2lnx
Integral on both sides
y=C2(xlnx-1)+C3

2. How to calculate the nth number of - 4, 8, - 16, 32, - 64?

The N + 1 power of (- 1) is multiplied by the n power of 2

In the multiplication formula of the right figure, each letter represents a number from 0 to 9, and different numbers represent different numbers. Then the letter D represents the number
The word is () a 2 B # C 2 or 3d4
Figure a × CB
　　　　　　ED
　　　　　GF
　　　　－－－－－－
　　　　　DDD

DDD = D * 111 = D * 3 * 37cb is a multiple of 37, which can only be 37 or 74. If CB = 37, then a = 3 * D, so a can only be 3,6,9a = 3 and C = 3 contradictory. If a = 6, then d = 2, ed = 6 * 7 = 42, GF = 6 * 3 = 18 (in this case, a = 6, B = 7, C = 3, d = 2, e = 4, f = 8, g = 1) if a = 9, then d = 3 and C = 3 contradictory. If CB = 74, then a = 3 * D / 2, then D is even

It is proved that the area of isosceles triangle is the largest among triangles with the same base and equal perimeter Answer by 12 noon tomorrow