A parabola has roots at 0.4 and -3. The equation is f(x) = 6-ax-bx². Find the value of b.

Question

anonymous · Answer

product of roots =constant/coeff. of x^2
so,
0.4*-3=-1.2=6/-b
b=6/1.2=5
:)

geerky42 · Answer

Wut? How come the product of roots = constant/coefficient of x² ?

geerky42 · Answer

@Aperogalics

anonymous · Answer

@geerky42 can u answer my simple answers?????????

geerky42 · Answer

What do you mean?

anonymous · Answer

i mean to say that give me answers of some simple questions related to this and u will get to know the answer.............r u ready?????????

geerky42 · Answer

Sure.

anonymous · Answer

ok 
0.4 and -3 are roots so (x-0.4) and (x-(-3)) are factors.....right

geerky42 · Answer

Yeah, (x-0.4)(x+3) = f(x)

f(x) is also equal to 6-ax-bx², right?

anonymous · Answer

yup:)
now see this|dw:1352583805197:dw|