Math Questions, Math Questions

1. The round log sawing three times will increase the bottom area by two square decimeters, the bottom area is 15 square decimeters, that is, square meters, and then multiplied by the length is 3 3 = 1 meter, and the volume is cubic meters.

2. This is a problem of examining the volume of cones and cylinders, first find the radius of the bottom surface of the cone, that is, (cm. The volume of the cone is (1 3)* cubic centimeters, and the bottom area of the cylindrical measuring cup is 314 square centimeters, which can be obtained by dividing by 314.

1.The area of 6 faces is increased, so the bottom area of the log is 30 6 = 5 dm, volume = length * bottom area = 30 * 5 = 150 dm.

2.Cone ground circumference = 2 r = cm r = 3 cm cone bottom area = r = 28 cm.

Cone volume = bottom area * height * 1 3 = 28 * 20 * 1 3 = cm.

Cylinder volume = bottom surface area * height = cylinder base area = r = cm.

Descending height = cm.

/4=3x2=6 30/6=5

Answer: The volume of each section of sawn logs is.

84/ 10x10=100

A: The water in the cup will go down.

Set the tangent coordinates with x1x2 and connect the straight line ellipses with Veda's theorem.

1.The idea is to find the inverse function of b(x), and then replace the x in a(b(x)=1+cos(x) with b -1(x), so that the left is a(b(b -1(x))a(x), and the right is what is sought.

The inverse function of is very easy to find, now we have y=sin(, we exchange x and y in the wide town, we get x=sin(, and after sorting, we get y=2arcsin(x), that is, b -1(x)=2arcsin(x).

3.Substituting b -1(x) into the first step, you can get a(x)=1+cos(b-1(x))=1+cos(2arcsin(x)), so your student's answer is correct.

1.First see if there are parentheses, and if there are parentheses, count the brackets first;

2.There are no parentheses, and the same level of operations is calculated in the order of simple play from left to right; Demolition slippery.

3.The two-level mixed operation without parentheses is calculated first, and the multiplication and division are calculated first, and then the addition and subtraction.

Parentheses precede multiplication and division before addition and subtraction If there are parentheses in a question, the parentheses are counted first, then multiplication and division, and finally addition and subtraction.

Parentheses precede multiplication and division before addition and subtraction.

1),（2-1）+（4-3）+（6-5）+.100-99)=1*50=50

2) Is it an integer part? That's 0.

Please use the printed version of the original question** to ask the question.

If the question is a[b(x)] = 1-cosx, b(x) = sin( x), then a[b(x)] = a[sin( x)] =1-cosx = 2[sin( x)] gives a(x) = 2x.

If the problem is a[b(x)] = 1+cosx, b(x) = sin( x), then a[b(x)] = a[sin( x)] =1+cosx = 1+1-2[sin( x)] = 2-[sin( x)] gives a(x) = 2-2x,

Solution, which is not completely inductive.

When n=1, it holds.

False n=k is not true.

Prove that n=k+1 is valid.

As the title, n=1, is true.

n=k, i.e., 1+,,2k-1=k 2,When n=k+1,1+2+,,2k-1+2k+1

k^2+2k+1

k+1) 2 is established.

Then 1+,,2n-1=n 2

n k 1 Ah, you can get it by directly bringing in the equation in the above column.

It brings n k+1 directly into the formula given in the question, so that it can be judged later.

Replace k + 1 with the whole thing, and you get this formula.

The first:

Second: Third: Fourth:

Because =

So 0.

So |π

-5×5+5÷5=-24

The ratio is large, so the number in the absolute value is positive, and you can go directly to the absolute value symbol, for I hope it can help you ......

5 divided by 5 minus 5 multiplied by 5 gives 24

6 minus 6 multiply 6 by 6 plus 6 to get 24a28

The first 5 5 5 5 24

The second -6-6-6-6=-24

The third should be A, because on the mullion on the calendar, any three numbers are three, and only a is not.

This number is 35

The factors of 35 are 1, 5, 7, 35

1/(n^2+n)=1/n-1/(n+1)

sn=1-1/2+1/2-1/3+1/3-1/4+…Stools are sold....+1 n-1 (n+1) is about the same as the jujube, and Lao Hongde sn=1-1 (n+1).

1 (n 2+n) = 1 n - 1 (n + 1) and then recursively. sn=1-1 2+1 2-1 Segment refers to 3+...1/n - 1/(n+1)

1-1/(n+1)

n comic return (n + 1).

Solution: Set ac x, bc hall friend y

In ACF and ABC, respectively, the cosine theorem is used to obtain the following

cf^2＝x^2＋1－x

y^2＝x^2＋4－2x

Because CF2AC*BC XY

So |xy＝x^2＋1－x

y^2＝x^2＋4－2x

x^2＋2x－1＝0

Solution. x 2 1 (negative root has been discarded).

So AC 2 1

If you don't learn the cosine theorem, then you can use C as CD AB and use the Pythagorean theorem to solve the problem, which is equivalent to proving the cosine theorem, and the process is just a little annoying).