MHT CET20227 Aug 2022Morning ShiftMathematicsProperties of TrianglesActual
In a triangle ABC , with usual notations A=60^ , then (1+ a c + b c ) (1+ c b - a b )=
Options
- A3 2
- B1 2
- C1
- D3
Correct answer
D. 3
Step-by-step solution
aligned & (1+ a c + b c ) (1+ c b - a b )= a+b+c c b+c-a b = (b+c)^2-a^2 b c & = b^2+c^2-a^2+2 b c b c =2 ( b^2+c^2-a^2 2 b c )+2 & =2 A+2=2 60^ +2=2 1 2 +2=3 aligned