the domain of the sqaure root (21x − 7)

Question

i cant figure out the domain the graph shows 0 to infinity but tit says its wrong

Answer 1

Remember that the domain is the x-value. We can't take the square root of a negative number.

 

21x - 7 ≥ 0

21x ≥ 7

x ≥ 1/3

 

[1/3,∞)