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Mr Brewin’s Year 8116 comments to Mr Brewin’s Year 8 |
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Hi
I am really stuck on Question 6 c and d. I don’t understand the brackets in an inverse function.
Holly
Hi Holly,
Is it 2(x+5) you don’t understand?
Use BODMAS: do the bracket first – add 5 to the x value, then multiply your answer by 2.
JT
Well, if it’s 2(x+5) then the function machine is:
x —> + 5 —–> x2
So the reverse would be:
x —> divided by 2 —> – 5
So it’s (x/2) – 5
i don’t understand question 5 of the homework [page 27]. how do i do it.
Hi
I was getting a little confused on question 5 page 27!
I don’t really understand what you have to do. I know that you have to fill in the table but I am not sure if you do the linear function formaula for all the numbers given in the table row ‘x’.
Hi Lucy,
For each of the x values given to you in the table, work out their y values by using the rule they give:
y = 3 times the x value, take away 2.
Hope that helps.
JT
Hi Ellie,
Yes. Take each x value in turn, and use the formula to calculate its y value. There are 7 sums to do.
JT
ok thanks!!
there is not a question 5 on page 30
Lara – it’s question 4 not 5.
JT
hi
i really dony understand question 6
on page 37
If you think it’s an equation, put =
If you think it’s an identity, put the one with 3 lines.
The difference is that an equation can be solved, whereas an identity just gives you 2 ways of writing exactly the same thing.
oh, ok i get it now thanks!
Hey,
I am really stuck on exercise 10.5 questions 3 and 4. I just need the formulas explained to me. :s
Hi Holly,
It means exactly what it says but remember to do things in the right order (BODMAS)
Q3 you pay £80 to hire the limo then £2 for every mile you travel in it.
Q4 4 x pi x radius-squared
JT
thanks