KCET2015MathematicsDifferentiation
If ( P = | array ll x & 1 1 & x array | ) and ( Q = | array lll x & 1 & 1 1 & x & 1 1 & 1 & x array | ),then ( d Q d x = )
Options
- A( 3 P+1 )
- B( 1-3 P )
- C( -3 P )
- D( 3 P )
Correct answer
D. ( 3 P )
Step-by-step solution
Given that ( P= | array ll x & 1 1 & x array |, Q= | array lll x & 1 & 1 1 & x & 1 1 & 1 & x array | ) So, ( P=x²-1 ) And ( Q=x (x²-1 )-(x-1)+(1-x) ) ( =x³-3 x+2 ) Now, ( d Q d x =3 x²-3 ) ( =3 (x²-1 )=3 P )