## Ask Singapore Homework?

Upload a photo of a Singapore homework and someone will email you the solution for free.

### See 2 Answers

Can I use number line?

If use number line have to trial and error. Using calculus can find the precise turning point

Turning points prove real roots?

Turning points mean maximum and minimum value

But how to show x is real

Solutions to turning points are values of x where max and min point occur

Don't need to prove x is real. It is assumed to be real in the question.

So the qns is something like " If x is real, find max and min value of the expression"

Why

Aaaa

I am so confuse

Min and max values can be found by equating its dy/dx = 0.

The easiest way is to plot the graph of the expression. There u can see the max and min point

And I think the qn has an error, it should include equality, ie ≤ and ≥

Note the double implication i used on each step, and in the end i mentioned "implying backwards".

I mean can you start off like that and do the "double implication". Issit legit?

A <=> B <=> C <=> D

Hence D => A

Correct?

Instead of going by your way of "indirect" proof I suppose? I'm not sure actually, I'm not a math major :/

So your "direct approach" is merely working backwards.

Neither am i a math major.. ;)

I didn't get it...

Wow why can you add the equal there

What is the meaning of implying backwards

qn meaning?

A B C D there I didn't get it too...

Maybe we should stick to calculus hahaha