How to do this math problem?

ab=18 AB is divided into three equal parts from AC=2BC, from D is the midpoint of the line segment AB, E is the midpoint of the line segment CB, and DE=6 gives 3DE=AB, so AB=18

Let ab=x,1 2*x-1 6*x=6, solution x=18, ad=18 2=9, cb=18 3=6, and the ratio of them is 3 to 2

Is this original or synchronous???

Let t = u, then u = t - dt = dui = 0, 2 >(t-sint)(1-cost) 2dt= u+sinu)(1+cosu) 2du= 1+cosu) 2du + u+sinu)(1+cosu) 2du

2 <0, 1+2cosu+(cosu) 2]du + 0 (odd function has a definite integral of 0 on a symmetric interval).

2π∫<0, π3/2+2cosu+(1/2)cos2u]du= 2π[3u/2+2sinu+(1/4)sin2u]<0, π3π^2

It's a simple 1+1=2 problem.

Because the vector pb multiplied by the vector pb = vector pb multiplied by the vector pc, then the vector pb multiplied by the vector pb - vector pb multiplied by the vector pc = 0, so the vector pb multiplied by (vector pa - vector pc) = 0 and the vector pb - vector pc = vector ca

So the vector pb is multiplied by the vector ca=0

So the vector pb vertical vector ca

The same can be said. Vector pa, vertical vector cb

Vector pc vertical vector ab

So point p is the intersection of the three heights of the triangle.

When the sides are equal in length, the area is the largest, so it is l 4

The root number is a quadratic function, its image is a parabola, the maximum value is taken at the extreme point, and the root number is required to be greater than 0, so the x range is there.

Eh: This math problem? I didn't see it.

Uh, this math problem should be done ...

The distance traveled by A is 1, and the time taken is t

Then the distance traveled by B is 1+1 5=6 5, and the time spent is t+(1 8)t=9 8t

So the speed at which A walks is 1 t

B walks at a speed of (6 5) (9 8)t

Therefore, the velocity ratio of A and B is (1 t) (6 5) (9 8) t) to get 15 16

Let s B = x, then s A = (1-1 5)x

Let t A = y, then t B = (1 + 1 8) y

Then v A v B = (s A t A) (s B t B) = [4x 5) y] x (9y 8)] 4x 5y) (9y 8x) = 9 10

Let the distance of A be x and the time is y, and the speed of A is x y, then the distance of B is (5 4)x, the time is (8 9)y, and the speed of B is [(5 4)x] 8 9)y].

So the velocity of A is faster than the velocity of B.

x/y ） 32/45

Set a walk for 4 5s, and it took time t; B walked the s, and it took 9t 8

Then the speed ratio is only (

Just simplify it 9:10

The distance of the first is 4L, and it is thought to be 5L; Time A 8t, B 9t, then the speed ratio 9 10

6+1=7 (pcs) Answer: Lao Wang has a total of 7 children.

Analysis] This question is like this, these 6 daughters have the same brother.

^3、 tana=-1/3

Let x=sina y=cosa x 2+y 2=1x+y=1 5 (x+y) 2=x 2+2xy+y 2 =1 25 2xy=1 25-1=-24 25

x-y) 2=x 2-2xy+y 2=1+24 25=49 25x-y= 7 5 (negative numbers rounded off cosa are negative).

20,000 km).

10,000 km) 10,000 km 3.38 million km.

A: A total of 3.38 million kilometers were flown through.

Hello! Radius = 10,000 km.

Circumference = 10,000 km.

A total of 10,000 kilometers were flown over.

Solution: Flight distance: 10,000 km) 1.18 million km.

10,000 kilometers is the radius.

The original 10,000 km) 10,000 km.

Solution: Multiply by 2 times by 77 turns.

De10,000 meters is equivalent to about 3.38 million meters.

Perimeter = 2 * r = 2 * 10,000 km).

77 * Perimeter = Total Length.