Motion and Differentiation (1 Viewer)

[Avenger6]

Hi, i'm stuck on the following question. If anyone could solve it and show me how you solved it, it would be greatly appreciated .

 

[Forbidden.]

My method is pretty crude eh?

You know that e^{log_e x} = x
(You can prove this if you want)

Let x = 3

So

3 = log_e (t + 1)

Using the above method (e^{log_e x} = x) by taking exponentials of both sides,

e³ = e^{log_e (t + 1)}

e³ = t + 1

.: t = e³ - 1

 

[tommykins]

回复: Motion and Differentiation

Finding t when x = 3

3 = ln (t+1)

e^3 = t+1

t = e^3 - 1

PS. Forbidden, can't you use just ln x = b as e^b = x?

 

[Forbidden.]

Re: 回复: Motion and Differentiation

Finding t when x = 3

3 = ln (t+1)

e^3 = t+1

t = e^3 - 1

PS. Forbidden, can't you use just ln x = b as e^b = x?

Provided they are rational numbers yes, according to the HSC's definition.
This is why I sometimes I run out of time in Maths exams, because I provide comprehensive workout lol.

 

[Avenger6]

Re: 回复: Motion and Differentiation

Great, thanks guys.