SOLUTION: A cubic polynomial function f(x) has leading coefficient -2 and intercepts the y-axis at 2. If f(1)=1, and f(-2)=-2, find f(-1) and write the complete function.
Algebra ->
Rational-functions
-> SOLUTION: A cubic polynomial function f(x) has leading coefficient -2 and intercepts the y-axis at 2. If f(1)=1, and f(-2)=-2, find f(-1) and write the complete function.
Log On
Question 1001291: A cubic polynomial function f(x) has leading coefficient -2 and intercepts the y-axis at 2. If f(1)=1, and f(-2)=-2, find f(-1) and write the complete function. Answer by Boreal(15235) (Show Source):
You can put this solution on YOUR website! ax^3+bx^2+cx+d=f(x)
when x=0, f(x)=2
a= -2
d=2
-2x^3+bx^2+cx+2=f(x)
f(1)=1
so -2+b-c+2=1
b+c=1
f(-2)= -2
16+4b-2c+2= -2
4b-2c=-20
b+c=1
==========
4b-2c= -20
2b+2c=2
6b=-18
b=-3
c=4
=========
-2x^3-3x^2+4x+2=f(x); f(1)=1; f(-2)=-2, f(-1)= -3 ANSWER
