Question

Let $\vec{a}=\hat{i}+4\hat{j}+2\hat{k}, \vec{b}=3\hat{i}-2\hat{j}+7\hat{k} \ and \ \vec{c} =2\hat{i}-\hat{j}+4\hat{k}.$ Find a vector $\vec{p}$ which is perpendicular to both $\vec{a} \ and \ \vec{b} \ and \ \vec{p} .\vec{c}=18$

Answer 1

very hard.... help me too