Induction (1 Viewer)

[Makematics]

Not sure if this should be in the extension 1 or extension 2 forum, but here goes. Sometimes questions in both extension 1 and extension 2 exams will ask you to prove some sort of inequality, sum, or something else. I have two questions regarding this.

1. If the preferred solution by the examiners involves an induction, will they explicitly state "by using induction prove ..."?

2. If the question does not ask you to do an induction and the preferred solution does not involve an induction, are you still allowed to perform an induction as your proof?

 

[Sy123]

Not sure if this should be in the extension 1 or extension 2 forum, but here goes. Sometimes questions in both extension 1 and extension 2 exams will ask you to prove some sort of inequality, sum, or something else. I have two questions regarding this.

1. If the preferred solution by the examiners involves an induction, will they explicitly state "by using induction prove ..."?

2. If the question does not ask you to do an induction and the preferred solution does not involve an induction, are you still allowed to perform an induction as your proof?

If the preferred solution is by induction, then they will normally ask for induction. For instance, they may ask to prove:

It is possible to prove so without induction by considering a telescoping sum, but they will say 'by using induction' if they want you to prove by induction.

If the question does not state 'use induction' yet induction can be used to complete the problem, then you are able to use induction and not be penalised if the question does not specify another method (i.e. use Binomial theorem).

 

[Makematics]

alright thanks heaps!

 

[cineti970128]

If the preferred solution is by induction, then they will normally ask for induction. For instance, they may ask to prove:

It is possible to prove so without induction by considering a telescoping sum, but they will say 'by using induction' if they want you to prove by induction.

If the question does not state 'use induction' yet induction can be used to complete the problem, then you are able to use induction and not be penalised if the question does not specify another method (i.e. use Binomial theorem).

so true +1
i will just say one quick thing
look at hsc past papers and there is at q 8 where they ask you to show LHS = RHS
it seems like you have to use anything other than Induction, but even my maths teacher said the question is impossible to be solved withoud induction
my advice is
if the q is like 4 mark, use the induction if you are really stuck and have some spare time.
the q is like 2 mark, just skip
dont get tricked by the statement, induction = safest way to get easy 4 marks

 

[braintic]

Look at the 1982 4 unit Probability question. One of the parts needs induction, but it does not suggest induction for you.