Question

Question 1(iv)

Use a suitable identity to get each of the following products:
$(3a-\frac{1}{2})(3a-\frac{1}{2})$

Answer 1

$(3a-\frac{1}{2})(3a-\frac{1}{2})={(3a-\frac{1}{2})}^2$
$=(3a{)}^2-2\times 3a\times \frac{1}{2}+{\left(\frac{1}{2}\right)}^2$ $\left[Usingtheidentity\right(a-b{)}^2=a^2-2ab+b^2]$
$=9a^2-3a+\frac{1}{4}$