AP EAMCET2010MathematicsProperties of Triangles
In a A B C, C=90^ . Then, a^2-b^2 a^2+b^2 is equal to
Options
- A(A+B)
- B(A-B)
- C(A+B)
- D(A-B)
Correct answer
B. (A-B)
Step-by-step solution
C=90^ , a^2-b^2 a^2+b^2 ...(i) c= a^2+b^2-c^2 2 a b = 90^ a^2+b^2-c^2 2 a b =0a^2+b^2-c^2=0 c^2=a^2+b^2 From Eq. (i), we get a^2-b^2 a^2+b^2 = a^2-b^2 c^2 a A = b B = c C =R (constant) = (R A)^2-(R B)^2 (R C)^2 = ^2 A- ^2 B ^2 90^ ( 90^ =1 )=( A+ B)( A- B)=2 A+B 2 A-B 2 2 A+B 2 A-B 2 =2 4 A-B 2 2 4 A-B 2 A+B= -C= - 2 = 2 =2 2 1 2 1 2 A-B 2 A-B 2 =2 ( A-B 2 ) ( A-B 2 ) 2 A=2 A A= [2 (A-B) 2 ]= (A-B) Hence, a^2-b^2 a^2+b^2 = (A-B)