Does y=(−1)xy = (-1)^x where x∈ℝx∈ℝ, change exponentially?

Is y = (-1)^x an exponential curve, or just a sinusoidal one, can it be said to change exponentially as with positive exponents? I’m sure W/A showed this as being sinusoidal with an integer period. But now shows the answer as -1. From the answers I understand that their is no definitive definition but their … Read more

Find the Limit: limx→2+e3/2(2−x)\lim_{x\to2^{+}}e^{3/2(2-x)}

\lim_{x\to2^{+}}e^{3/2(2-x)} Properties of the Natural Exponential Function: The exponential function f(x)=e^x is an increasing continuous function with domain \mathbb R and range (0, \infty). Thus e^x>0 for all x. Also \lim_{x\to-\infty}e^x=0 and the \lim_{x\to\infty} e^x=\infty So the x-axis is a horizontal asymptote of f(x)= e^x. How do I utilize this definition to solve this problem? … Read more

Compute limx→0ex−1x\lim\limits_{x \to 0} \frac{e^x-1}{x} without using derivatives [duplicate]

This question already has answers here: Proving that limx→0ex−1x=1 (7 answers) Closed 6 years ago. How to compute limx→0ex−1x without using derivatives? Every method I can think of gives me some indeterminate form. Answer Set  ex−1=y, so  x=ln(1+y) and  y→0 for  x→0 Now you have:  limx→0ex−1x=limy→0yln(1+y)=limy→01ln(1+y)y=limy→01ln(1+y)1y Putting  1y=t, for  y→0,t→∞ , so you have:  limt→∞1ln(1+1t)t=1ln(e)=1 … Read more

The value of the series \frac{e^{-n}}{n}\frac{e^{-n}}{n}

I have already found that the series \sum_{n=1}^{+\infty} \frac{e^{-n}}{n} converges. However, I want to find its value, but I don’t know how to do that. I’ve tried several things but without success. Need your help ! 🙂 Answer HINT: Let f(x)=\sum_{n\ge 1}\frac{x^n}n; then f'(x)=\sum_{n\ge 1}x^{n-1}=\sum_{n\ge 0}x^n\;. You know a closed form for f'(x), and you … Read more

Solving $ax=e^{bx}$ [duplicate]

This question already has answers here: How can one find the zeroes of $f(x)=ae^{bx}+cx+d$? (3 answers) Closed 3 years ago. I’ve been asked by a friend to help him solve this equation, but since we couldn’t find the right answer, I thought about posting it here. Firstly, I thought about derivating both sides and get: … Read more

How to derive ∞∑k=01k!\sum\limits_{k=0}^\infty \frac{1}{k!} from lim\lim\limits_{n\to\infty}\left(1+\frac{1}{n}\right)^n

Is it possible to derive \begin{align*} e=\sum\limits_{k=0}^\infty \frac{1}{k!} \end{align*} from \begin{align*} e=\lim\limits_{n\rightarrow \infty}\left(1+\frac{1}{n}\right)^n \end{align*} ? Thank you:)! Answer If you use the binomial expansion you get \left(1+\frac 1n\right)^n=1+n\cdot \frac 1n+\frac {n(n-1)}{2!}\left(\frac 1n\right)^2+\frac {n(n-1)(n-2)}{3!}\left(\frac 1n\right)^3\dots==1+1+\frac 1{2!}\left(1-\frac 1n\right)+\frac 1{3!}\left(1-\frac 1n\right)\left(1-\frac 2n\right)+\dots I will leave you to conclude. AttributionSource : Link , Question Author : Kevin Meier , … Read more