Question

5. If a and B are the zeros of the quadratic polynomial f(x) = x²-x-4, find the value of 1/a+1/b-ab​

Answer 1

Answer:

Given p(x)=ax³-x²+x+4

Since -1 is a zero of p(x)

p(-1)=0

Replace x by (-1) in p(x) we get p(-1).

p(-1)=a(-1)³-(-1)²+(-1)+4

0=a(-1)-1–1+4

-a-2+4=0

a=4–2

a=2.