Moderate -0.5 This is a standard C1 coordinate geometry question requiring calculation of gradient of AB, finding perpendicular gradient, then using point-slope form. It's slightly easier than average as it follows a routine algorithmic procedure with no conceptual challenges, though the 5 marks indicate multiple steps (gradient calculation, perpendicular gradient, equation formation, rearrangement to required form).
The points \(A\) and \(B\) have coordinates \((3, 4)\) and \((7, -6)\) respectively. The straight line \(l\) passes through \(A\) and is perpendicular to \(AB\). Find an equation for \(l\), giving your answer in the form \(ax + by + c = 0\), where \(a\), \(b\) and \(c\) are integers. [5]
The points $A$ and $B$ have coordinates $(3, 4)$ and $(7, -6)$ respectively. The straight line $l$ passes through $A$ and is perpendicular to $AB$. Find an equation for $l$, giving your answer in the form $ax + by + c = 0$, where $a$, $b$ and $c$ are integers. [5]
\hfill \mbox{\textit{Edexcel C1 Q4 [5]}}