Showing working

[kenhung123]

For questions that require substitution to get an answer and its worth 2 marks which indicates I need to show working, is saying when x=5 then y=25 sufficient or I need to show the substitution in the function? E.g. y=5x so y=5(5)=25 or short cut when x=5, y=25.

Of course this isn't such a big deal when working with something like that but I am saying for huge functions or functions with constants such as ln(5) etc are used, it is pretty annoying to write the whole thing out just to show working.

[the.watchman]

I always write the whole thing out, but I'm not sure how necessary it is

[kenhung123]

Also wondering if you can do to find mean. (Similarly with median) Or do I need to write what h(t) equals? I mean mathematically it seems correct since they are equivalent so it shouldn't make a difference but solutions usually show the expression, perhaps it is more clear to the reader?

Also, if a function isn't written with that notation, can we define it ourselves? E.g. y=5x I write "Let f(x)=5x" if I am able to write f(x) to find mean, median, definite integral, indefinite integral and derivatives, it would save lots of time.

[Jdog]

teacher said with integrals make sure you have the sqaure bracket as a step if it is worth more than a mark.

Yours would be fine im assuming, ask your teacher jst in case

[kenhung123]

Oh, I'm talking about in exams. Yea that is true, what your teacher said.

[Martoman]

For questions that require substitution to get an answer and its worth 2 marks which indicates I need to show working, is saying when x=5 then y=25 sufficient or I need to show the substitution in the function? E.g. y=5x so y=5(5)=25 or short cut when x=5, y=25.

Of course this isn't such a big deal when working with something like that but I am saying for huge functions or functions with constants such as ln(5) etc are used, it is pretty annoying to write the whole thing out just to show working.

I'd say it is, if only because they want to see what you are doing, and this is where that other mark in the 2 or 3 mark question would lie. It only takes a second in any case and helps you see where you have gone wrong if you have.

For your mean question, unless the function is defined in the question (or you define it) then write it out because thats where your answer mark will come from.

[m@tty]

Just to be safe show more working rather than less, if in doubt.

Time shouldn't be a problem.