well, geez, just plug in the values. You have
(x-1)(x+3)
= x^2 + 2x - 3 = x^2 + (a+1)x + b
Now it should be clear what a and b are if the two polynomials are identical.
If the zeroes of the quadratic polynomial x^2+(a+1)x+bare 1& -3 find a&b
3 answers
Most likely the topic is the Sum and Product of roots of a quadratic
for ax^2 + bx + c = 0
sum of roots = -b/a
product of roots = c/a
given:
sum of roots = -3+1 = -2
product of roots = -3
then -(a+1) = -2
a = 1
b/1 = -3
b = -3
for ax^2 + bx + c = 0
sum of roots = -b/a
product of roots = c/a
given:
sum of roots = -3+1 = -2
product of roots = -3
then -(a+1) = -2
a = 1
b/1 = -3
b = -3
oh, yeah. Good call.
3 answers