# Domain of a function (1 Viewer)

#### cossine

##### Active Member
So with this question i sort of used logic, x can’t be zero and the inside can’t equal zero to get my domain. What would be the actual mathematical way of solving this?View attachment 36136View attachment 36137
x can’t be zero. ?? x can equal zero however x cannot be less than 0 because you cannot take the square root of a negative number.

3- sqrt(x) >= 0
-sqrt(x) >= -3
sqrt(x) <= 3
=> x <= 9 # Note x must also greater than or equal to zero because of the square root.
Therefore 0<= x <= 9

#### Hivaclibtibcharkwa

##### 𝗕𝗶𝗼𝗹𝗼𝗴𝘆 𝗧𝘂𝘁𝗼𝗿
x can’t be zero. ?? x can equal zero however x cannot be less than 0 because you cannot take the square root of a negative number.

3- sqrt(x) >= 0
-sqrt(x) >= -3
sqrt(x) <= 3
=> x <= 9 # Note x must also greater than or equal to zero because of the square root.
Therefore 0<= x <= 9
Yea that’s what I did on my working out image above, also typo I meant cannot be less than zero. So that seems to be the only method to solve this

#### cossine

##### Active Member
Yea that’s what I did on my working out image above, also typo I meant cannot be less than zero. So that seems to be the only method to solve this
I am not sure what you mean by actual mathematical way in your original post.

• Hivaclibtibcharkwa