/sci/ - Science & Math

[Anonymous No.1046986]

I am helping someone out with math, and I am having an absolute brain fart. I am wondering if you can help me with this one.
I know I am supposed to use logs or natural logs, but completely forgot how to use them properly. (other than the basic rules x=b^y, then y=logb(x) stuff)

Thomas invests 1,200 into an account with a rate of 4%. How many years will it take to have 15,400. And they want me to use the A=P(1+r)^t equation.

Thanks in advance,

Your fellow anon.

[Anonymous No.1046998]

Bump for a need of assistance with my basic retardation levels.

[Kittens !!xU3iFlQ1LBB No.1047013]

Are you retarded? Principle = 1200, Amount = 15400, rate = 4%. This is fucking plug and chug. And I've told you nothing that isn't already given to you.

[Anonymous No.1047011]

Disguised homework thread is disguised.

The principle is 1200. The rate 0.04. The accumulated is 15400.

<span class="math">15400 = 1200 \cdot {1 + 0.04}^{t}

Divide.

<span class="math">\frac{154}{12} = 1.04^{t}[/spoiler].

Take log of both sides:

<span class="math">\log {\frac{154}{12}} = t \cdot \log {1.04}[/spoiler]

Finish by dividing again. Or subtracting, if you're in the mood to use that rule.[/spoiler]

[Anonymous No.1047029]

<span class="math">15400 = 1200 \cdot {(1 + 0.04)}^{t}[/spoiler]

Divide.

<span class="math">\frac{154}{12} = 1.04^{t}[/spoiler]

Take log of both sides:

<span class="math">\log {\frac{154}{12}} = t \cdot \log {1.04}[/spoiler]

Finish by dividing again. Or subtracting, if you're in the mood to use that rule.

[Anonymous No.1047041]

>>1047029
Hmmm, thanks. I must have plugged something in wrong the first time I took that exact step.

Thank you very much.

[Anonymous No.1047069]

>>1046986

> Implying brain can fart