How to prove basic inequality with vector

How to prove basic inequality with vector

Let m = (√ a, √ b) and N = (√ B, √ a)
Then the quantity product m * n = √ AB + √ AB = 2 √ ab
And m * n = | m | * | n | cos = √ (a + b) * √ (a + b) cos = (a + b) cos
So (a + b) cos = 2 √ ab
Because cos ≤ 1, so (a + b) cos ≤ a + B, that is 2 √ ab ≤ a + B

The area of rectangle ABCD is 48 square centimeters. EF is the midpoint of AB and BC respectively. The area of triangle DEF is () square centimeters
Formula, and analysis, thank you very much, thank you very much

A triangle is a rectangle with an area of 1 / 4 = 12

It is known that f (x) is an odd function tangent f (x + 2) = f (x) when 0

If f (x) is an odd function, then f (x) = - f (- x)
And f (x + 2) = f (x)
a=f(6/5)=f(-4/5+2)=f(-4/5)=-f(4/5)=-lg(4/5)
b=f(3/2)=f(-1/2+2)=f(-1/2)=-f(1/2)=-lg(1/2)
c=f(5/2)=f(2+1/2)=f(1/2)=lg(1/2)
-lg(1/2)>-lg(4/5)>lg(1/2)
So b > a > C

For a grain store, there is a cylinder below and a cone above. Measure from the inside, the diameter of the bottom is 2m, and the height of the cylinder and cone is 3M. Calculate the volume

Bottom radius
2 △ 2 = 1 (m)
What is the volume of a cylinder
1 × 1 × 3.14 × 3 = 9.42 (M3)
What is the volume of a cone
1 × 1 × 3.14 × 3 × 1 / 3 = 3.14 (M3)
What is the volume of the grain farm
9.42 + 3.14 = 12.56 (M3)

If 3a2bn and 4amb4 are similar, then M=______ ，n=______ ．

If the solution ∵ 3a2bn and 4amb4 are of the same kind, then M = 2, n = 4, so the answer is: 2, 4

A triangle, its bottom is 20.5cm, its area is 65.6cm, how high is it?

65.6×2÷20.5=6.4

Is the number within 50 odd or composite? Write the number within 50 odd or prime?
Brother,

9,15,21,25,27,33,35,39,45,49

Given that the circumference of a circle is (π a + 2 π b) cm, then the area of the circle is () CM & # 178;

It is known that the circumference of a circle is (π a + 2 π b) cm, then the area of the circle is (π (a + 2b) &# 178 / 4) CM & # 178;

As shown in the figure, AB is the diameter of ⊙ o, and P is a point on the extension line of ab. the tangent of ⊙ o is made through P, and the tangent point is C, PC = 23. If ∠ cap = 30 °, then the diameter of ⊙ o is ab=______ ．

Connect BC, let the diameter of the circle be x, then the triangle ABC is a triangle with an angle of 30 °, BC = 12ab, triangle BPC is an isosceles triangle, BC = BP = 12ab, ∵ PC is the tangent of the circle, PA is the secant of the circle, ∵ PC2 = PB · PC = 12x · 32x = 34x2, ∵ PC = 23, ∵ x = 4, so the answer is: 4

As shown in the figure, line AB = 16cm, C is the point on AB, M is the midpoint of AC, n is the midpoint of BC, then Mn=______ cm．

∵ m is the midpoint of AC, n is the midpoint of BC, Mn = MC + CN = 12ac + 12bc = 12ab = 8cm