Find the value of the polynomial 5x – 4x2 + 3 at (i) x = 0 (ii) x

1.	Find the value of the polynomial 5x – 4x2 + 3 at (i) x = 0 (ii) x = -1 (iii) x = 2
Answer» (i) f(x) = 5x – 4x² + 3 x = 0 then, f(0) = 5(0) – 4(0)² + 3 =0 – 0 + 3 f(0) = 3 (ii) f(x) = 5x – 4x² + 3 x = -1 then, f(-1) = 5(-1) – 4(-1)² + 3 = -5 – 4(+1) + 3 = -5 – 4 + 3 = -9 + 3 f(-1) = -6 (iii) f(x) = 5x – 4x² + 3 x = 2 then, f(2) = 5(2) – 4(2)² + 3 = 5(2) – 4(4) + 3 = 10 – 16 + 3 = 13 – 16 f(2) = -3

Find the value of the polynomial 5x – 4x2 + 3 at (i) x = 0 (ii) x = -1 (iii) x = 2

Answer»

(i) f(x) = 5x – 4x² + 3 x = 0 then,

f(0) = 5(0) – 4(0)² + 3

=0 – 0 + 3

f(0) = 3

(ii) f(x) = 5x – 4x² + 3

x = -1 then, f(-1) = 5(-1) – 4(-1)² + 3

= -5 – 4(+1) + 3 = -5 – 4 + 3

= -9 + 3 f(-1) = -6

(iii) f(x) = 5x – 4x² + 3

x = 2 then,

f(2) = 5(2) – 4(2)² + 3

= 5(2) – 4(4) + 3

= 10 – 16 + 3

= 13 – 16

f(2) = -3