How to find the number of terms in the summation formula of equal ratio sequence,

How to find the number of terms in the summation formula of equal ratio sequence,

When q is not equal to 1, the formula Sn = A1 * (1-Q ^ n) / (1-Q)
The formula of finding the number of items in equal ratio sequence
The general formula of equal ratio sequence is: an = A1 * q ^ (n-1)
If the general term formula is transformed to an = A1 / Q * q ^ n (n ∈ n *), then an can be regarded as a function of the independent variable n when Q > 0, and the points (n, an) are a group of isolated points on the curve y = A1 / Q * q ^ X
N-1 = (an / A1) open n-th radical
N = (an / A1) open n times root sign + 1
If we know the common ratio Q, the first term a and the last term B, the number of terms n = [(logb loga) / logq] + 1
In the continuous equal time interval T, the displacement difference is constant, S1 in the first interval and S2 in the second interval, then the acceleration of the object is
The displacement difference is constant, which indicates that the object is accelerating or decelerating uniformly
S2-S1=aT^2
a=(S2-S1)/T^2
This is an important deduction of acceleration, the original topic in the book
Rational number addition and subtraction method, know to see ah!
One winter day in a city, the highest temperature is - 11 degrees. The weather forecast says that a strong cold air will affect the city in the north. The next day, the temperature will drop by 10 degrees to 20 degrees. Using the above information, please estimate that the highest temperature in the city the next day will not be higher than how many degrees? The lowest temperature will not be lower than how many degrees?
The maximum temperature is - 11 ° - 10 ° = - 21 ℃
The lowest temperature is - 11 ° - 20 ° = - 31 ℃
So the maximum temperature will not be higher than - 21 degrees
The minimum temperature will not be lower than - 31 ℃
A + B + C = () a × B × C = () a-b-c-d = () please help me
a+b+c=a+(b+c)
a×b×c=a×(b×c)
a-b-c-d=a-(b+c+d)
Why (S1 / T1) / (S2 / T2) = (S1 / S2) / (T1 / T2)
Dividing by a number is equal to multiplying by the reciprocal of the number, fractional multiplication equals numerator multiplication as numerator, and denominator multiplication as denominator
So (S1 / T1) / (S2 / T2) = (S1 / T1) * (T2 / S2) = (S1 * T2) / (T1 * S2) = (S1 / S2) * (T2 / T1) = (S1 / S2) / (T1 / T2);
This problem is mainly a number of positive and negative transformation. Refueling!
Dividing by a number is equal to multiplying by the reciprocal of the number, provided that the number cannot be zero. Follow up: please write down the process of change
Mathematical problem of "rational number, addition and subtraction of rational number"
1. Minus two and one seventh divided by minus five fourths equals zero________
2. If the value of 3x + 5 is opposite to that of 7x-15, what is the value of X? (expression)
3. Known - 2
1. Minus two and one seventh divided by minus five fourths
= (-15/7)/(-5/14)
=6
2、3X+5=-(7X-15)
10X=10
X=1
3、|X-7|+|X+4.5| -2
The answer is 6
2.X=1
1. 2 1 / 7 = 15 / 7, 15 / 7 divided by 5 / 14 = 6
2、3X+5=-（7X-15），x=1
3、-2
(B + C) multiply d = () multiply () + () multiply () = () + () fill in the blanks according to the operation law
(B + C) times d = (b) times (d) + (c) times (d) = (BD) + (CD)
(B + C) times d = (b) times (d) + (c) times (d) = (BD) + (CD)
Do not understand can ask, help please adopt, thank you!
(B + C) times d = (b) times (d) + (c) times (d) = (BD) + (CD)
（b+c)*d=b*d+c*d=bd+cd
b*d+c*d=bd+cd
(B + C) times d = (b) times (d) + (c) times (d) = (BD) + (CD)
When an object is moving in a straight line with uniform acceleration, the displacement in time T1 is S1, and the displacement in time T2 after that time is S2
In the uniformly accelerated linear motion, the instantaneous velocity at the midpoint of a period of displacement time = the average velocity of this period of displacement
T = (1 / 2) T1 is the midpoint of S1, and the velocity at t is V1 = S1 / T1
T '= T1 + (T2) / 2 is the midpoint of S2, and the velocity at t' is V2 = S2 / T2
a=(V2-V1)/(T'-T)=(S2/t2 -S1/t1)/{[t1+(t2)/2]-(1/2)t1}
=2(S2*t1-S1*t2)/[t1*t2(t1+t2)]
Let the velocity be v
Vt1-1/2at1^2=S1
Vt2+1/2at2^2=S2
Namely:
Vt1t2-1/2at2t1^2=S1t2
Vt2t1+1/2at1t2^2=S2t1
From the following formula to the above formula:
1/2at1t2(t2-t1)=S2t1-S1t2
A = 2 (s2t1-s1t2) / (t1t2 (t2-t1))
Mathematical problems of rational number addition and subtraction
Three and a quarter plus minus three fifths plus three fourths plus minus eight and two fifths
How much is it?
Translation numbers
1 3 3 2
3- + -5- + - + -8-
4 5 4 5
The original formula is three and a quarter plus three quarters minus three fifths minus eight and two fifths
=4-9
=-5
13/4-3/5+3/4-42/5=13/4+3/4-(3/5+42/5)=-5
Equal to - 5.5
Solution: the original formula = 3 + 1 / 4 + (- 3 / 5) + 3 / 4 + (- 8 + 2 / 5)
=2。 65+0。 75+（-8.4）
=3.4+(-8.4)
=-5
The original formula = three and a quarter + three quarters - three fifths - eight and two fifths
=4-9
=-5
In Word 2003, scores can be
Insert - domain: domain name EQ - domain code - options: switch to add to the domain. Fill in numerator on the left and denominator on the right of the domain code "," below.
Solution: the original formula = 3 / 1 / 4 + (- 3 / 5) + 3 / 4 + (- 8 / 2 / 5) (Note 3 and 1 / 4 are written as 3 / 1 / 4)
=(3/1/4+3/4)+((-3/5)+(-8/2/5))
=4+(-9)
=-5
Three and a quarter plus minus three fifths plus three fourths plus minus eight and two fifths
Equal to three and a quarter plus three quarters plus (minus three fifths plus minus eight and two fifths)
Equal to 4 + (- 9)
Equal to - 5
Solution: the original formula = 3 + 1 / 4 + (- 3 / 5) + 3 / 4 + (- 8 + 2 / 5)
=2。 65+0。 75+（-8.4）
=3.4+(-8.4)
=-2