Question
Question: If the points \((a,b),(a',b')\) and \((a - a',b - b')\) are collinear, then....
If the points (a,b),(a′,b′) and (a−a′,b−b′) are collinear, then.
A
ab′=a′b
B
ab=a′b′
C
aa′=bb′
D
a2+b2=1
Answer
ab′=a′b
Explanation
Solution
a′−aa−a′−a′=b′−bb−b′−b′
⇒a′−aa−2a′=b′−bb−2b′ ⇒a′a=b′b⇒ab′=a′b