Determine The domain of the function.

• Oct 25th 2010, 10:15 PM
Chief
Determine The domain of the function.
1 f(x)=-10
2 f(x)=25
3 f(x)=5x-10
4 f(x)=-x+3
5 f(x)=mx+b
6 f(x)=-ax
7 f(x)=25-x2 ( 2 is square on x)
8 f(x)=x2-x (2 is square on x)
9 f(x)=(x+4) Under root

I didnt attend my last lecture and here ar esome question i dont know how to solve and tomorrow is last date to submit assignment please kindly solve these questions in a porper way.thanks :)
• Oct 26th 2010, 01:06 AM
earboth
Quote:

Originally Posted by Chief
1 f(x)=-10
2 f(x)=25
3 f(x)=5x-10
4 f(x)=-x+3
5 f(x)=mx+b
6 f(x)=-ax
7 f(x)=25-x2 ( 2 is square on x)
8 f(x)=x2-x (2 is square on x)
9 f(x)=(x+4) Under root

I didnt attend my last lecture and here ar esome question i dont know how to solve and tomorrow is last date to submit assignment please kindly solve these questions in a porper way.thanks :)

1. All your functions depend on the variable x even though x isn't "visible". But for instance
$f(x) = -10$ is the same as $f(x)=0\cdot x -10$ and here you have your x.

2. You have to prove for each function if there exist any constraints of x such that the term f(x) can't be calculated.
The constraints you are supposed to know are:

i) The denominator of a fraction must unequal zero.
ii) The radical of a square-root must be non-negative.
iii) The argument of a logarithm-function must be positive.

3. There is only one function in your list whose domain isn't $\mathbb{R}$
• Oct 26th 2010, 06:23 PM
mr fantastic
Quote:

Originally Posted by Chief
1 f(x)=-10
2 f(x)=25
3 f(x)=5x-10
4 f(x)=-x+3
5 f(x)=mx+b
6 f(x)=-ax
7 f(x)=25-x2 ( 2 is square on x)
8 f(x)=x2-x (2 is square on x)
9 f(x)=(x+4) Under root

I didnt attend my last lecture and here ar esome question i dont know how to solve and tomorrow is last date to submit assignment please kindly solve these questions in a porper way.thanks :)