Answer:
[tex]4x^2y^2-2x^4y+\dfrac{1}{4}x^6[/tex]
Step-by-step explanation:
[tex]\text{Use the formula:}\\(a-b)^2=a^2-2ab+b^2[/tex]
[tex]\biggr(2xy-\dfrac{1}{2}x^3\biggr)^2\\\\=(2xy)^2-2.(2xy)\biggl(\dfrac{1}{2}x^3\biggl)+\biggl(\dfrac{1}{2}x^3\biggl)^2\\\\=4x^2y^2-2x^4y+\dfrac{1}{4}x^6[/tex]
