Thread: fitting polynomial functions into data

create the equation of a cubic polynomial f(x) that has a double zero at (0,0) a single zero at (-3,0) and that passess through (1,16)

i understand that (x+3) is a factor but how would you find a ... how would you answer this question?? please help this is for my summative i also considered subbing y and x (1,16) into the formula for finding a and all i got in the end was this: f(x)=4x^2(x+3)

Originally Posted by magmagod

create the equation of a cubic polynomial f(x) that has a double zero at (0,0) a single zero at (-3,0) and that passess through (1,16)

i understand that (x+3) is a factor but how would you find a ... how would you answer this question?? please help this is for my summative i also considered subbing y and x (1,16) into the formula for finding a and all i got in the end was this: f(x)=4x^2(x+3)

A zero at (0,0) means that (x - 0) divides f(x)

f(x) = C(x)(x)(x + 3)

C is a constant.

Use the point (1,16) to solve for C.

Oh, you added that last bit on afterwards and I didn't see it. Yep, you got the right answer!