Convert the square root to its exponential form and then use the power rule.
y=√x=x12
Now bring the power of 12 down as a coefficient and then subtract 1 from the current power of 12. Evaluate the fractions and simplify. Manipulate exponents from negative to positive.
y′=12x(12−1)=12x(12−22)=12x(−12)=12x12=12√x