Chapter 5 - Section 5.3 - Special Products - Exercise Set - Page 367: 35

$4x^2-\dfrac{1}{4}$

Using $(a+b)(a-b)=a^2-b^2$ or the special product of the sum and difference of like terms, the product of the given expression, $ \left( 2x+\dfrac{1}{2} \right)\left( 2x-\dfrac{1}{2} \right) ,$ is \begin{array}{l}\require{cancel} 2x(2x)-\dfrac{1}{2}\left( \dfrac{1}{2} \right) \\\\= 4x^2-\dfrac{1}{4} .\end{array}