HSC - উচ্চতর গণিত ১ম পত্র→অধ্যায়-০২ঃ ভেক্টর (HSC - গণিত)→ডট গুণন

Points $\vec{A} \text { and } \overrightarrow{\mathrm{B}}$ lieon a straight line $\vec{\ell} \text { relative to a fixed origin 0. Point } \vec{A}$ has position vector $\hat{\mathrm{i}}-3 \hat{\mathrm{j}}+2 \hat{k} \text {, }$ point $\overrightarrow{\mathrm{B}}$ has position vector $-2 \hat{\mathrm{i}}+2 \hat{\mathrm{j}}-\hat{\mathrm{k}}$ and point $\overrightarrow{\mathrm{C}}$ has position vector $2 \hat{\mathrm{i}}+p \hat{\mathrm{j}}-4 \hat{\mathrm{k}}$ with respect to 0 $ where p is a constant. Given that $\overrightarrow{A C}$ is perpendicular to $\vec{\ell}$ Find the valuc of p $