Gujarat BoardEnglish MediumSTD 11 ScienceMATHSSTRAIGHT LINES1 Mark
MCQ
If line joining (1, 2) and (7, 6) is perpendicular to line joining (3, 4) and (11, x):
A
12
B
16
✓
-16
D
-12
✓
Answer
Correct option: C.
-16
-16
Solution:
We know, slope of line joining two points $(x_1, y_1)$ and $(x_2, y_2)$ is given by $\frac{(\text{y}_{2}-\text{y}_{1})}{(\text{x}_{2}-\text{x}_{1})}$
Lines are perpendicular means $m_1\times m_2 = -1$
$\Rightarrow\big(\frac{\text{x}-4}{11-3}\big), \big(\frac{6-2}{7-1}\big) = -1$
⇒ (x - 4) (4) = (-1) (8) (6)
⇒ x - 4 = -12
⇒ x = -16.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.