For the expression f(x) = x3 + ax2 + bx + c, if f(1) = f(2) = 0 and f(4) = f(0). The values of a, b & c are
Answers
Step-by-step explanation:
..........................
a=-4;b=5;c=-2
mark my answer as BRAINLIEST
Given:
f(x) = x³ + ax² + bx + c.
f(1) = f(2) = 0, f(4) = f(0).
To Find:
values of a, b, and c
Solution:
According to the question,
x³ + ax² + bx + c = 0
for f(1),
(1)³ + (a×1²) + b×1 + c = 0
1 + a + b + c = 0 -----Equation(1).
for f(2),
(2)³ + (a×2²) + b×2 + c = 0
8 + 4a + 2b + c = 0 -----Equation(2).
for f(4) = f(0),
(4)³ + (a×4²) + b×4 + c = (0)³ + (a×0²) +(b×0) + c.
64 + 16a + 4b + c = 0 + 0 + 0 + c.
64 + 16a + 4b +c = c.
64 + 16 a + 4b = 0.
16 + 4a + b = 0.
b = -16 - 4a.-----Equation(3).
Putting equation (3) in equation(1),
1 + a - 16 - 4a + c = 0.
- 15 - 3a + c = 0.
c = 15 + 3a.---------Equation (4).
Putting equations (3) and (4) in equation (2),
8 + 4a - 32 - 8a + 15 + 3a = 0.
- 9 - a = 0.
a = -9.
Putting the value of a in equation (3),
b = - 16 - 4 × -9.
b = 20.
Putting the value of a in equation (4),
c = 15 + 3 × -9.
c = -12.
Hence, the values of a, b and c are -9, 20, and -12.