Question

Find a quadratic polynomial the sum and product of whose zeroes are -8 and 12 respectively. Hence find the zeroes.

Answer 1

Step-by-step explanation:

We khow the sum and the product of the zeroes of this quadratic polynomial

Here is a trick :

when we khow the sum S and the product P ofvtwo numbers we can find them by solving :

x²-Sx+p=0

here S= -8 and P=12

so:

x²+8x+12=0

Let Δ be the discrminant of this equation: a= 1 , b= 8 and c=12

Δ= 8²-4*12 =16

the zeros are:

(-8-4)/2= -6

(-8+4)/2 = -2

verify:

-6+(-2)= -8

-2*(-6)= 12

now the polynomial quadratic is:

(x+6)(x+2)