Thread: values of roots

hi, the question i've got is:

the polynomial has (x - 2) as a factor

find the exact values of the roots of the equation

could someone show me step by step how you would arrive at the answer please? thankyou

Originally Posted by mark

hi, the question i've got is:

the polynomial has (x - 2) as a factor

find the exact values of the roots of the equation

could someone show me step by step how you would arrive at the answer please? thankyou

Where a,b and c are constants. You can find a, b and c by comparing coefficients

Spoiler:

.These will be of the form P(x) = (x-2)(ax^2+bx+c)

:

:

(constant) :

Therefore

i already did that bit, the answer in the book is , and

any ideas on how to arrive at that answer?

Originally Posted by mark

i already did that bit, the answer in the book is , and

any ideas on how to arrive at that answer?

The roots are where it equals 0 at.



So either or

The book's answers are the solutions to those equations

ok thanks, how would you get to and from though? what formula would you use?

Originally Posted by mark

ok thanks, how would you get to and from though? what formula would you use?

The quadratic formula:

For :

ahhhh the quadratic formula, thanks for the help