Because \displaystyle \sqrt{3} is equal to \displaystyle 3^{1/2}, then \displaystyle \sqrt{\sqrt{3}} = \sqrt{3^{1/2}} = \bigl(3^{1/2}\bigr)^{1/2} = 3^{\frac{1}{2}\cdot\frac{1}{2}} = 3^{1/4}.