Another MX2 question (1 Viewer)

[U MAD BRO]

Please help me with this question and this one too http://community.boredofstudies.org/showthread.php?t=287805 and I will stop posting questions

I'm going to bed now, I'm extremely tired, please try to solve this question for me

 

[Carrotsticks]

1994 HSC, Question 7.

 

[U MAD BRO]

1994 HSC, Question 7.

haha, so it's copied !

 

[U MAD BRO]

what about this question, is it 1994?
otherwise can you give me a hint
man, questions 7 and 8 are hard!

 

[ssj12345]

for question 7(a):
basically differentiate and find your turning points.
for a cubic, if there are three distinct roots then u have a max and min turning point
therefore f(x-value for max)*f(x-value for min)<0
after that it's a piece of cake

with 7(a)(i) just draw a diagram and do some reasoning and use that identity plus reasoning for (ii)