# exponential

1. ### Exponential expansion

I've got a cell line with a gene that gets bigger exponentially. I cultured the cells from 16/1/17 for 295 days and the gene expanded exponentially. For the second culture, cells from culture 1 frozen on 22/5/17 (d127), were thawed on 2/1/18 and cultured for 196 days. For the third culture...
2. ### Hi I'm new and have a problem with exponential equation.

So I'm a Swede and found this site in an attempt to solve a game problem. I have a weapon that do 50 dps and damage more per second to a maximum of 200 dps and it maxes out in 45 seconds. 200 - 50 = 150 150 / 45 = 3,33... So it does 3,33 extra damage per second. Now i want to know how...
3. ### Modelling tetrahedral numbers

Hi, I hope someone can help. I'm trying to solve for a): I developed the equation y = 4^x, where "x" represents an additional 4 sides. This equation works perfectly well, however, it is different from the textbook's solution. The textbook's solution is the following: Can someone please...
4. ### Exponential function word problem

Hi, I hope someone can help. My textbook has been extraordinarily incorrect with its solutions in the past, so I want to make sure with the following questions that my textbook is wrong in this case and not the other way around. As follows: Can someone please let me know what solution they...
5. ### Graphing exponential functions

Hi, I hope someone can help. I'm trying to calculate what the instantaneous rate of change would be at year 2 for the following table: I'm suppose to plot these points on a graphing calculator and then find the values of y (students per computer) that are close to year 2, then use these...
6. ### Exponential equation word problems

Hi, I hope someone can help. I'm trying to solve the following question: As stated above, the equation is N(t) = 3^(t+1). N(t) represents the number of people told during the hour t, and t = 1. However, let's say that we wanted to develop an equation which fit the same context that...
7. ### Help with exponential generating function proof

Use exponential generating functions to prove that: P(n) = P(n-1) + n, with n >= 1 and P(0) = 1 will result in this equation: P(n) = (1/2)n2 + (1/2)n + 1 I know how to do this with generating functions, you just plug in n=1, n=2, n=3,.... P(1) will result in (1/2)(1)2 + (1/2)(1) +1 which is 2...
8. ### Exponential generating functions help understanding

Use exponential generating functions to prove that: P(n) = P(n-1) + n, with n >= 1 and P(0) = 1 will result in this equation: P(n) = (1/2)n2 + (1/2)n + 1 I know how to do this with generating functions, you just plug in n=1, n=2, n=3,.... P(1) will result in (1/2)(1)2 + (1/2)(1) +1 which is 2...
9. ### Exponential Functions and Equations - Practice Test

hellooo, i'm having some trouble completing an exponential functions practice test, please help!!! please don't use logarithms as i haven't learnt about them and the unit does not cover them. i am attaching a pdf file below, the practice test is on the last two pages! it would be great if you...
10. ### Implicit Differentiation

y^2 = e^(xy) y' = ye^(xy) / [ 2y - xe^(xy) ] Is it wrong if my final answer written Like this? y = sqrt[ e^(xy) ] y' = ( sqrt[ e^(xy) ] )e^(xy) / [ 2( sqrt[ e^(xy) ] ) - xe^(xy) ]
11. ### Limit of Infinity for Exponential Absolute Function

Find the indicated limit. lim as x goes infinity of |(x + 1) / (x - 2)|^(x^2 - 4)^(1/2)
12. ### Solve for x in an exponential equation

I found this equation in the grade above's (year 12) textbook, and I've been trying for a day to solve it with full working out. e^(2x)-e^(x)-2=0 I'm just not sure what working out I need to do. If anybody could post the answer with full working out, it'd be much appreciated.
13. ### Exponential Models and Applications

Can someone please help me with this problem: The population (in millions), p and q, of two neighbouring American states, P and Q, over a period of 50 years from 1950 are modelled by functions p = 1.2 x 2^0.08t and q = 1.7 x 2^0.04t. Find when the population of state P is: a) equal to the...
14. ### Exponential Models and Applications

Hi everyone, so I'm doing some worded questions but they are hard for me to understand. The half-life of plutonium-239 is 24,000 years. If 10 grams are present now, how long will it take until only 10% of the original sample remains (give your answer to the nearest year). Some worked examples...
15. ### exponential to logarithm

Hi; I need to convert f(x) = 2(3/4)^((x+3)/2) - 8 to logarithmic form. y + 8 = 2(3/4)^((x+3/2) y/2 + 4 = (3/4)^((x+3)/2) log(y/2 + 4) = ((x+3)/2)log(3/4) not sure where to go from here or is it all wrong? Thanks.
16. ### convert transformed log to exponential

Hi; Trying to convert y = -2log(base3/4)(1/2x + 4) -3 to exponential form. what I did switch x and y: x = -2log(base3/4)(1/2y + 4) - 3 add 3 to both sides: x + 3 = -2log(base3/4)(1/2y + 4) divide both side by -2: (x + 3)/-2 =...
17. ### Exponential Growth and Decay Problem.

At the start of an experiment, 2 x 10^4 bacteria are present in a colony. Eight hours later, the population is 3 x 10^4. (a) determine the growth constant k. (b) what was the population two hours after the start of the experiment? Formula for this: N=N_o(e)^(kt) N= is the sum of answer...
18. ### Numerov method on a exponential grid mesh

Hi there. I was trying to implement Numerov method for solving second order differential equations (you can see some information of Numerov algorithm at here: https://en.wikipedia.org/wiki/Numerov%27s_method ). At the beginning I've used a uniform grid mesh, all points equally spaced. I'm...
19. ### Gamma and exponential distribution

I think I'm about to lose my mind. I'm relearning gamma and exponential distribution. I know that exponential distribution is a special case of gamma, that is when alpha is equal to 1. Also I know that exponential distribution deals with measuring the waiting time until a random event happens...
20. ### exponential equation problem ~~

Hi So my question is asking me to solve for x in the formula t=-5\log{\frac{5-x}{5}} my final answer came out to be x= (^5\sqrt{3125 -\frac{3125}{10^t}}) i have attached my work to see how i got there but i feel as i did something wrong any help would be great thanks.