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VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Mathematical Methods CAS => Topic started by: h_seabs on March 13, 2021, 08:35:56 pm

Title: Need some help with 3/4 functions question :)
Post by: h_seabs on March 13, 2021, 08:35:56 pm
Hey Y'all,

Could someone give me a step-by-step explanation on how to solve the question in the image attached? Thank you so much :D

– Hunter
Title: Re: Need some help with 3/4 functions question :)
Post by: fun_jirachi on March 13, 2021, 09:18:28 pm
Hey :D

It's important to show us what you've tried in future questions - it helps further your understanding more than us just giving you the answers. That being said, here are a few hints:

Q1

Notice that this tells you that if the function is even, the function is constant!

The logic for Q2 follows much the same line as Q1 - you assume that \(-f(x) = f(-x)\) and then work through some similar algebra as the above to find \(f(x)\) in terms of q. If you really can't work through this part, let us know

What Q3 is essentially asking is for the inverse function of \(f(x) = \frac{3x+8}{x-3}\) ie. find a function such that \(x = \frac{3y+8}{y-3}\), but rearranged so \(y\) is a function of \(x\). It also asks for solution(s) to \(\frac{3x+8}{x-3} = x\) which is going to be a quadratic that you have to solve - again if you really can't work through this, let us know

Hope this helps :)
Title: Re: Need some help with 3/4 functions question :)
Post by: h_seabs on March 14, 2021, 02:35:26 pm
Hey :D

It's important to show us what you've tried in future questions - it helps further your understanding more than us just giving you the answers. That being said, here are a few hints:

Q1

Notice that this tells you that if the function is even, the function is constant!

The logic for Q2 follows much the same line as Q1 - you assume that \(-f(x) = f(-x)\) and then work through some similar algebra as the above to find \(f(x)\) in terms of q. If you really can't work through this part, let us know

What Q3 is essentially asking is for the inverse function of \(f(x) = \frac{3x+8}{x-3}\) ie. find a function such that \(x = \frac{3y+8}{y-3}\), but rearranged so \(y\) is a function of \(x\). It also asks for solution(s) to \(\frac{3x+8}{x-3} = x\) which is going to be a quadratic that you have to solve - again if you really can't work through this, let us know

Hope this helps :)

Ah! Thank you so much : ) I've got it now  ;D