Which numbers are irrational? Select each correct answer.

15−−√

21−−√

−9√

14√

Step-by-step explanation:

square root of 15 is 3.8=irrational

square root of 21 is 4.58=irrational

square root of -9 is doesn't have a real square root

square root of 14 is 3.7 =irrational

my guess is

step-by-step explanation:

the height of the surface increases from the center out to the sides of the road.

step-by-step explanation:

as we move out we move away from the x-axis.

and as mentioned in the problem statement that height of a road increases when we move away from the center x.

hence proved that 3rd option

the height of the surface increases from the center out to the sides of the road.

is the correct option.