Eric Nicholas K's answer to whowhatwherewhy's Secondary 3 A Maths Singapore question.
done
{{ upvoteCount }} Upvotes
clear
{{ downvoteCount * -1 }} Downvotes
Substitutions help greatly for this type of question.
But first, you need to know that e^3x can be written as (e^x)^3 under standard rules of indices.
Also, any positive number raised to a real power will always be positive, so e^x can never throw out a value of zero.
But first, you need to know that e^3x can be written as (e^x)^3 under standard rules of indices.
Also, any positive number raised to a real power will always be positive, so e^x can never throw out a value of zero.
Date Posted:
2 years ago
thankyouusomuchh
Please don't write 'FAIL' in exam, Angelina. It is improper presentation and an inappropriate word.
The better word to use is 'Rejected' or the shorthand 'N.A' (stands for Non-Applicable)
The better word to use is 'Rejected' or the shorthand 'N.A' (stands for Non-Applicable)
Furthermore, you would have been taught the logarithm conversion (as specified in your syllabus)
b = aⁿ ↔ logₐb = n
So we can save two steps by simply writing
eˣ = 2
x = ln 2 (recall ln represents logₑ)
Instead of having to take on both sides.
Likewise, instead of writing
eˣ = 1
eˣ = e⁰
x = 0
We can skip the middle step since it is understood that any number, raised to the power of 0, is always equal to 1.
(Except 0⁰, where there is still divided opinion over whether it is indeterminate or 1)
b = aⁿ ↔ logₐb = n
So we can save two steps by simply writing
eˣ = 2
x = ln 2 (recall ln represents logₑ)
Instead of having to take on both sides.
Likewise, instead of writing
eˣ = 1
eˣ = e⁰
x = 0
We can skip the middle step since it is understood that any number, raised to the power of 0, is always equal to 1.
(Except 0⁰, where there is still divided opinion over whether it is indeterminate or 1)