solve fully

4. Given the equation on the plane m: F = (2, 0, 1) + s(4, 2, -1) + t(-1,1,2), s, t ER, determine the equation of the line, in parametric form, that intersects the plane at (2, 0, 1) and is perpendicular to the given plane, I. [4] 5. If la+ 6|= Ja-b, then prove using dot product, that the non-zero vectors, a and b, are perpendicular. [4]