AP EAMCET202123 Aug 2021Evening ShiftMathematicsStraight LinesActual
The angle between the straight lines 3 x+4 y+9=0 and x-7 y-22=0 is
Options
- A4
- B6
- C3
- D8
Correct answer
A. 4
Step-by-step solution
Given, straight lines are l₁: 3 x+4 y+9=0 ...(i) l₂: x-7 y-22=0 ...(ii) Slope of line l₁= - Coefficient of x Coefficient of y m₁= -3 4 Slope of line l₂= -1 -7 m₂= 1 7 Let be the angle between lines l₁ and l₂ . = | m₁-m₂ 1+m₁ m₂ | aligned & = | -3 4 - 1 7 1+ ( -3 4 ) ( 1 7 ) | & = | -25 28 28 25 | aligned =1 = 4