# Question Video: Finding the Domain of Root Functions Mathematics

Find the domain of the function 𝑓(𝑥) = √(7𝑥 − 7).

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### Video Transcript

Find the domain of the function 𝑓of 𝑥 is equal to the square root of seven 𝑥 minus seven.

In order to find the domain, we need to set what’s inside the square root to be greater than or equal to zero because we wanna take the square root of positive numbers. If we would take the square of negative numbers, we would end up having imaginary numbers because we can’t take the square root of negative numbers unless we use imaginary.

So our first step would be to add seven to both sides. So we have seven 𝑥 is greater than or equal to seven. And now we need to divide both sides by seven. So we have that 𝑥 is greater than or equal to one. So that means we can plug in one and anything bigger than one. So our domain would be one to infinity, with a bracket on one since we can actually plug-in that number.

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