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1. (Original post by john1234567)
for question 8 you could change cot2x=0 to cos2x/sin2x=0 and so you have cos2x=0. i did the same as you though
however there don't seem to be any solutions in the given range i really hope i got all seven marks there
2. any idea on high grade boundaries will be?
3. i hope so, i dropped about 22 marks i think according to arsey's solutions :/
4. argh i dont want to wait for marchhh!!!!
5. (Original post by Arsey)
Very hard I thought. Here are my solutions
=) myonly doubt was finding a & b but i guess it should be right considering you & plenty of other people also got the same answer
6. For Question 8

and

For ..... so x = 22.5, 112.5

For cot2x = 0, even though it said Math error on the calculator, if you somehow remembered the graph, you would remember that the graph cuts the x-axis!

You get and thats at 2x = 90, 270....Thus, x = 45, 135 as well

OR
I just saw a better way of doing it:

Thus

Thus , Thus x = 45, 135
7. (Original post by john1234567)
also for the last question (the range of fg) i got it's >4 because the minimum is already at the point (1,1) before the +3
Someone told me that aswell, I didn't understand what he meant but it was something to do with from the function f but I didn't know how it would work so I just put
8. (Original post by .:excel4100%:.)
x = 45, 135 as well
but if you plug that into the equation you get a math error because you're dividing by tan90 and tan270
9. (Original post by john1234567)
....
On a glance it looks like we got the same answers for most of them. The only real question which I had to think about was the differentiate x=tany one, got there in the end though. I think it went very well, hoping for near 100.
10. (Original post by john1234567)
for question 8 you could change cot2x=0 to cos2x/sin2x=0 and so you have cos2x=0. i did the same as you though
of course, so 45 and 135 will also work.
11. (Original post by milliondollarcorpse)
On a glance it looks like we got the same answers for most of them. The only real question which I had to think about was the differentiate x=tany one, got there in the end though. I think it went very well, hoping for near 100.
i smiled when i saw that cos it looked like the method for differentiating arcsinx
12. I think I dropped 20 marks overall. Should still be a high B with adjusted UMS I think.
13. (Original post by john1234567)
also for the last question (the range of fg) i got it's >4 because the minimum is already at the point (1,1) before the +3
not sure what you mean but if you use x>1 then fg>3
14. (Original post by john1234567)
but if you plug that into the equation you get a math error because you're dividing by tan90 and tan270
But when you put it back into the equation:

Remember at those points, so you don't need to put any values in for those, so it's effectively just:

and the answers to that are at and
15. I thought it was an alright exam, according to arsey's answer, the only mistakes I made were the same one as him
16. for question 8 if you got the right answers but you also solved for tan2x=0 then how many marks you lose? for q4 i diffrentiate it right but when i simplify it i got it wrong. how many marks would i lose?
17. (Original post by john1234567)
i smiled when i saw that cos it looked like the method for differentiating arcsinx
I don't know how to differentiate arcsinx, lucky I still managed to do it anyway
18. (Original post by Kd3239)
for question 8 if you got the right answers but you also solved for tan2x=0 then how many marks you lose? for q4 i diffrentiate it right but when i simplify it i got it wrong. how many marks would i lose?
i cant believe i made some silly mistakes
19. (Original post by .:excel4100%:.)
Remember at those points, so you don't need to put any values in for those
i'm not sure i agree with that. if cot2x = 0 then you should be able to put x=45 in and get 0
20. (Original post by .:excel4100%:.)
For Question 8

and

For ..... so x = 22.5, 112.5

For cot2x = 0, even though it said Math error on the calculator, if you somehow remembered the graph, you would remember that the graph cuts the x-axis!

You get and thats at 2x = 90, 270....Thus, x = 45, 135 as well

OR
I just saw a better way of doing it:

Thus

Thus , Thus x = 45, 135
I got the same first 2 solutions as this, but for the last ones i'm not too sure. Oh, and for the ranges/domains on the last questions, did people get x greater than one and fg greater than or equal to 3

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