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# C3 graph with a constant

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1. can anyone help with part c please? I am not sure if a is positive or negative so do I just assume a is 0? Thanks Attachment 584256584258
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2. expand it first

you should be able to solve for the intersection and roots once you do so
3. (Original post by coconut64)
can anyone help with part c please? I am not sure if a is positive or negative so do I just assume a is 0? Thanks
You can't assume it's zero.

In this case "a" cannot be negative, otherwise you'll be raising a negative number to a real power - what's - which can't be sketched in a standard graph as it involves complex numbers.

Note that if a >1, the exponential will be increasing.
If a < 1 then it's decreasing.
And if a=1 ?

Can you take it from there.
4. (Original post by anonmouse221)
expand it first

you should be able to solve for the intersection and roots once you do so
wHAT DO i EXPAND?
5. (Original post by ghostwalker)
You can't assume it's zero.

In this case "a" cannot be negative, otherwise you'll be raising a negative number to a real power - what's - which can't be sketched in a standard graph as it involves complex numbers.

Note that if a >1, the exponential will be increasing.
If a < 1 then it's decreasing.
And if a=1 ?

Can you take it from there.
if a is 1 then I will get 1/x +1 and 1+1 for a^x+a...
6. (Original post by coconut64)
if a is 1 then I will get 1/x +1 and 1+1 for a^x+a...
Confusing. How can you get two different expressions when you set a=1, into part c?

However, if a=1, then part c reduces to 1+1, and so, f(x)=2, i.e. constant.
7. (Original post by ghostwalker)
Confusing. How can you get two different expressions when you set a=1, into part c?

However, if a=1, then part c reduces to 1+1, and so, f(x)=2, i.e. constant.
I am slightly lost too. There are 3 parts in part c and each part requires you to draw a graph. I don't get what you mean by f(x)=2 , so it is just a straight line?? Thanks
8. (Original post by coconut64)
I am slightly lost too. There are 3 parts in part c and each part requires you to draw a graph. I don't get what you mean by f(x)=2 , so it is just a straight line?? Thanks
Sorry, I thought you were just looking at the last part of part C, which is also called (c).

This is a slightly unfair question, IMO, as the shape of the graph depends on the value of "a", If a >1, then its increasing, if a < 1 it's decreasing, and if a=1, it's a constant - i.e. just a straight line at y=2.
9. (Original post by ghostwalker)
Sorry, I thought you were just looking at the last part of part C, which is also called (c).

This is a slightly unfair question, IMO, as the shape of the graph depends on the value of "a", If a >1, then its increasing, if a < 1 it's decreasing, and if a=1, it's a constant - i.e. just a straight line at y=2.
Sorry about the confusion! So what do I set a as ? It says a is just an arbitrary constant....
10. (Original post by coconut64)
Sorry about the confusion! So what do I set a as ? It says a is just an arbitrary constant....
It's arbitrary so, you can't set it as anything. I'd suggest drawing three graphs, one for each of the different scenarios.
11. (Original post by ghostwalker)
It's arbitrary so, you can't set it as anything. I'd suggest drawing three graphs, one for each of the different scenarios.
thanks

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