MHT CET202020 Oct 2020Morning ShiftMathematicsProperties of TrianglesActual
with usual notations, if triangle ABC is right angled at C , then ( a ²+ b ² a ²- b ² ) ( A - B )=
Options
- A3
- B1
- C0
- D-1
Correct answer
B. 1
Step-by-step solution
Given that in ABC , m C =90^ A + B =90^ (1) Then aligned & a²+b² a²-b² (A-B) =& (k A)²+(k B)² (k A)²-(k B)² (A-B) [ a A = b B =k ] =& ² A+ ² B ² A- ² B (A-B)= 1- 2 A+1- 2 B 1- 2 A-1+ 2 B (A-B) =& 2-( 2 A+ 2 B) 2 B- 2 A (A-B) =& 2-[2 (A+B) (A-B)] -2 (A+B) (B-A) (A-B) =& 2-[(0) (A-B)] 2 (A+B) (A-B) (A-B) =& 2 2 (A+B) = 1 90^ =1 aligned