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# In need of maths clever people. C3 watch

1. I am stuck on the second part of this question. It's been bugging me for about an hour and I don't understand what it's asking me to do. Would really appreciate some help and pozzz rep in it.

The even function f is defined over the domain -4>(or equal to) x (or equal to)< 4 by

f(x)=x, 0<(or equal to) x <2

f(x)= 4-x, 2>(or equal to) x (or equal to)< 4

[a] Sketch the graph of f over its domain. GOT THIS.

[b] Find all the values of x for which

f(x)= (x+4)/4

Thanks
2. (Original post by chussell)
I am stuck on the second part of this question. It's been bugging me for about an hour and I don't understand what it's asking me to do. Would really appreciate some help and pozzz rep in it.

The even function f is defined over the domain -4>(or equal to) x (or equal to)< 4 by

f(x)=x, 0<(or equal to) x <2

f(x)= 4-x, 2>(or equal to) x (or equal to)< 4

[a] Sketch the graph of f over its domain. GOT THIS.

[b] Find all the values of x for which

f(x)= (x+4)/4

Thanks

Well, in the interval 0 to 2 for instance f(x) = x, therefore you are looking for solutions to x = (x+4)/4 which lie in that interval. If the solution doesn't lie in that interval then you're not interested in it.

Similarly for the other intervals.

Edit2: Remove alternate suggestion; nowt wrong with it, just not useful in this circumstance.
3. For (b) you need to consider the cases and separately.

So you need to solve two equations: the first is (and ), and the second is (and ). Remember in each case only to accept roots which are in the given ranges of x.
4. Thanks I seem to understand it a bit more now. However, this will seem very dumb, but what do you use as the values of x to plug in to the equations ? For some reason functions has me very, very confused.
5. (Original post by chussell)
Thanks I seem to understand it a bit more now. However, this will seem very dumb, but what do you use as the values of x to plug in to the equations ? For some reason functions has me very, very confused.
You don't plug in any values, you need to solve them.

For example if you had then you'd rearrange to get and so ... just solve the two equations, and make sure that the answer you get (e.g. 1 in my example) lies in the necessary range of values of x.
6. You sir, are a legend. Thanks a lot .
7. Hopefully you now have 4 solutions:
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