Question

03
If a, b, and c satisfy the equation x3 - 3x2 + 2x + 1 = 0
then choose the value of
1/a+ 1/b+1/ c​

Answer 1

Answer:

-2

Step-by-step explanation:

this question requires knowledge of chapter 4 of class 10 NCERT

in this equation, a=1 , b=-3, c=2 and d =1     (general form: ax3+bx2+cx+d = 0)

the sum of a, b, c and d is -b/a

hence,   -(-3)/1

sum of roots = 3

product of roots:   -d/a

hence,     -1/1

product of roots:  -1

sum of roots taken two at a time:   c/a

hence,   2/1

sum of roots taken two at a time:  2      (ab +bc +ca)

(keep in mind that the roots are a, b and c)

now begins the fun part,

1/a+1/b+1/c

ab + bc + ca/abc

=2/-1

-2 is the correct answer