Question

find a quadratic polynomial whose one of the zero is minus 15 and sum of the zero is 42

Answer 1

Let x, y be the zeroes of the quadratic polynomial.

Given that sum of the zero is 42.

= > x + y = 42.  ----- (1)

Given that one of the zero is -15.

x = -15.  ---- (2)


Substitute (2) in (1), we get

= > -15 + y = 42

= > y = 42 + 15

= > y = 57


Now,

The product of zeroes = -15 * 57

                                      = -855.


The required Quadratic polynomial is;

= > x^2 - (S)x + P = 0

= >  x^2 - (42x) + (-855) = 0

= > x^2 - 42x - 855 = 0.


Hope this helps!

Answer 2

let the other zero be x

now,

acc to question:

x-15=42

x= 42+15

x= 57

we know that,

sum of zeroes = -b/a

57-15=42

also,

product of zeroes= c/a

57 x -15= -855

on comparing it with ax^2+bx+c ,

we have,

x^2-42x-855