A-Level Maths: B8-05 Functions: Restricting the Domain

[@jamontoast1414]

ur a beast at maths, thanks for the help

[@TickerzYT]

is there a video on restricting a domain to make an inverse function possible? like making forcing it to be a 1to1 function

[@phantomr277]

Hi, I was wondering, do we have to learn piecewise functions for the AQA spec? It appears on the Edexcel spec but I’m not sure.

[@TLMaths]

Piecewise functions are not a specific part of the Edexcel spec or any of the specs - it is not mentioned in qualifications.pearson.com/content/dam/pdf/A%20Level/Mathematics/2017/specification-and-sample-assesment/a-level-l3-mathematics-specification.pdf - a quick search for the word piecewise reveals nothing. A piecewise function could at most be used for the purposes of drawing a transformed graph after a stretch / reflection / translation but that's about it.

[@anisamalik8854]

Hi, when you restricted the domain, where did the 5 come from?

[@TLMaths]

I chose it

[@divine7168]

He needs 2 specific co-ordinates of x to restrict the domain and to find the upper value for the restricted range

[@yashwinipraba6482]

@@divine7168 so i can pick any values ?

[@endaodonnell]

Tutorial s are excellent

[@johnsmith-hs8oi]

Hi Sir, On my topic list it says functions (mappings). Do you think this would also include inverse functions?

[@TLMaths]

It could do - you might want to check with your teacher.

[@sanyuyi]

Hi: is there any video in which you explain how to transform a many to one function into a one to one function? Thanks

[@TLMaths]

I'm assuming by transform, you don't mean a graph transformation in the true sense. This video describes precisely what you're describing - restricting the domain of the many-to-one function to make it one-to-one.

[@sanyuyi]

@@TLMaths Thank you for your answer. The exercise I was talking about is this one: Given a function f defined by y=3(x-4)to the power of 2 +12, x =R. Find a one to one function defined by the same rule as f. Why the answer is >or = to 4?

[@TLMaths]

The curve y=3(x-4)^2+12 has its stationary point at (4,12). So x>=4 is a domain that would give you all possible values of y, and would make it one-to-one. www.desmos.com/calculator/bblg0bdfl9

[@sanyuyi]

@@TLMaths Thanks once again. I’ll check all your videos to fully understand this issue.

[@ulagainesippavanbabuk2371]

Great.