Concept:
In SHM, velocity at displacement \(x\) is:
\[
v=\omega\sqrt{A^2-x^2}
\]
and maximum velocity is:
\[
v_{\max}=\omega A
\]
Step 1: Given:
\[
v=\frac{v_{\max}}{2}
\]
Step 2: Substitute:
\[
\omega\sqrt{A^2-x^2}=\frac{\omega A}{2}
\]
Step 3: Cancel \(\omega\):
\[
\sqrt{A^2-x^2}=\frac{A}{2}
\]
Step 4: Square both sides:
\[
A^2-x^2=\frac{A^2}{4}
\]
\[
x^2=A^2-\frac{A^2}{4}
\]
\[
x^2=\frac{3A^2}{4}
\]
Step 5:
\[
x=\frac{\sqrt3A}{2}
\]
\[
\boxed{\frac{\sqrt3A}{2}}
\]