How to count the number of items in the equal ratio sequence I know that the equal difference is the number of terms = (last first) / tolerance + 1 How to calculate the ratio, for example, 2 ^ 3 + 2 ^ 4 + 2 ^ 5 +. 2 ^ n + 1

How to count the number of items in the equal ratio sequence I know that the equal difference is the number of terms = (last first) / tolerance + 1 How to calculate the ratio, for example, 2 ^ 3 + 2 ^ 4 + 2 ^ 5 +. 2 ^ n + 1

When each term of the equal ratio sequence is written in the form of the same base power, the exponent becomes the equal difference sequence. Therefore, you only need to calculate the number of exponents according to the formula above. As many exponents as there are, there are as many terms

Half (x + 1) - 6 (x + 1) = 1 to solve the equation

1 / 2 (x + 1) -- 6 (x + 1) = 1 to get: (x + 1) -- 12 (x + 1) = 2 to get: x + 1 -- 12x -- 12 = 2 to move items: X -- 12x = 2 -- 1 + 12 to merge similar items: - - 11x = 13 to divide both sides and 11

Mom and dad work hard (composition) 300 words,

Dad, mom, I would like to say thank you first! In order to thank you for your upbringing, I would also like to say, you have worked hard, in order to thank you for working hard for me. Mom and Dad, you regard me as a pearl, hold me in your hand, do not dare to hold too hard, for fear of crushing; do not dare to hold too loose, for fear of falling to the ground

Let a, B, C, d be real numbers, and a ^ 2 + B ^ 2 = 1, C ^ 2 + D ^ 2 = 1, then what is the minimum value of ABCD?

a^2+b^2=1,c^2+d^2=1
Let a = Sint, B = cost, C = sinm, d = COSM
abcd=sintcostsinmcosm=(1/4)sin2tcos2t
-1/4

How to solve the equation

x÷25×4=100
x=100x25÷4
x=625

1. Cuboid and cube volume calculation formula can be unified as?
2. If the edge length of a cube is 60cm, its surface area is () square centimeter and its volume is () cubic centimeter
3. The edge length of a cube is 3DM. If it is cut into two identical cuboids, the surface area will be increased by () square centimeter. The volume of each cuboid is () cubic decimeter

1. Bottom area multiplied by height

Given that sina-3cosa = 0, then sin2a / cos & # 178; a-SiN & # 178; a=

sina-3cosa=0
tana=3
sin²a+2cos²a
=(sin²a+2cos²a)/(sin²a+cos²a)
=(tan²a+2)/(tan²a+1)
=(9+2)/(9+1)
=11/10
Are you satisfied with the above answers?

Find the range of y = 4 / 3x + √ (9-x ^ 2)
∵9-x^2≥0
∴-3≤x≤3
Let x = 3sina, a ∈ [- π / 2, π / 2]
∴y=3cosa+4sina

y=f(a)=3cosa+4sina,a∈[-π/2,π/2]
Let sinm = 3 / 5, COSM = 4 / 5, then Tam = 3 / 4
y=f(a)=5Sin(a+m)
The minimum value of F (a) is f (- π / 2) = - 4
The maximum value of F (a) is 5
Then the range is [- 4,5]

[mathematics · quadratic function] it is known that the quadratic function y = AX2 + BX + C has a maximum value of 2 when x = 2, and the length of the line segment of the image cut on the x-axis is 2,
It is known that the quadratic function y = AX2 + BX + C has a maximum value of 2 when x = 2, and the length of the line segment cut by the image on the x-axis is 2

Given the quadratic function y = AX2 + BX + C, when x = 2, there is a maximum value of 2, and the length of the line cut by the image on the x-axis is 2. Find the analytic expression of the quadratic function
When x = 2, there is a maximum value of 2, indicating that the opening of this function is upward
The axis of symmetry is x = 2
The length of the line cut by the image on the X axis is 2,
Then the distance between the two intersections of quadratic function and X axis is 2
Because the two intersections are symmetric with respect to x = 2, the distance between the two intersections x = 2 is 1
That is, the two intersections are (1,0), (3,0)
That is y = a (x-1) (x-3)
2 = a (- 1) because it passes through point (2,2)
a=-2
So y = - 2 (x-1) (x-3)
=-2x²+8x-6

If the image of function y = (2a-3) x passes through two or four quadrants, the value range of a is__

The coefficient of X is negative when passing through quadrants 2 and 4
So 2a-3