Answer:
Solving the expression: [tex]\sqrt{(\sqrt{21}-2\sqrt{7} )^2}[/tex] we get [tex]\sqrt{21}-2\sqrt{7}[/tex]
Step-by-step explanation:
We need to solve the expression: [tex]\sqrt{(\sqrt{21}-2\sqrt{7} )^2}[/tex]
We know that [tex]\sqrt{x} = x^{\frac{1}{2}}[/tex]
Solving:
[tex]\sqrt{(\sqrt{21}-2\sqrt{7} )^2}\\=((\sqrt{21}-2\sqrt{7} )^2)^\frac{1}{2}[/tex]
We know that [tex](a^2)^\frac{1}{2}=a[/tex]
= [tex]\sqrt{21}-2\sqrt{7}[/tex]
So, solving the expression: [tex]\sqrt{(\sqrt{21}-2\sqrt{7} )^2}[/tex] we get [tex]\sqrt{21}-2\sqrt{7}[/tex]