Maths help !

[cHeStEr]

3b 5 8 9c in
http://www.xtremepapers.me/CIE/Cambridg ... _sp_4a.pdf


Help me plz

Thanks

I'll get more doubts

Thanks again

 

[Aahmsil]

Question 5

Okay, I can answer question 5 for now.

Part (a) (i)
Since y = f (x)
When they say find the value f (0) [notice that the 'x' has been replaced with a zero], they indirectly mean find the value of y when x = 0.
When you do find the value it will be 3.

Part (a) (ii)
Apply the same logic here as well.
Since y = f (x)
When they say find the value f (8) [notice that the 'x' has been replaced with an eight], they indirectly mean find the value of y when x = 8.
When you do find the value it will be around -4.

Part (b) (i)
This uses the opposite logic to the previous question and you're required to find the value of x when the value of y is given.
Notice that in the equation y = f (x), y has been replaced with 0.
Answer to this has three values:
-1.6,2,8.6

Part (b) (ii)
Use the same method but here unlike in the previous one, there will only be one answer; 9.2

Part (c)
Again the question states; f (x) = k. So k is a y value.
You have to find two y values which give two x values.
The answers here are:
3 and -9
Work it out on the graph and see !!!

Part (d)
Generally if a line is leaning forwards like this / , it is said to have a positive gradient.
Backward bending lines like this \ have a negative gradient.
So look for the portion of the graph that bends backwards.
You'll find that it is in the interval 0<x<6
This is the answer !!!
You cannot effectively measure a horizontal graph period using y values hence we use x values.

I'll try helping with the others as well but I'm a bit busy right now

Hope that helped !!!

Cheers !!! :good: