Question

find the value of the polynomial 5x - 4x² + 3 at X = 1 and X = - 2​

Answer 1

Question ➡

Find the value of the polynomial 5x - 4x² + 3 at X = 1 and X = - 2

Answer ➡

$5x - {4x}^{2} + 3 \: at \: x = 1 \\ \\ 5(1) - {4(1)}^{2} + 3 \\ \\ 5 - 4 + 3 \\ \\ 1 + 3 \\ \\ = 4$

Therefore value of the polynomial 5x - 4x² + 3 at X = 1 is 4

$5x - 4 {x}^{2} + 3 \: at \: x = - 2 \\ \\ 5( - 2) - {4( - 2)}^{2} + 3 \\ \\ - 10 - 16 + 3 \\ \\ - 26 + 3 \\ \\ = - 23$

Therefore value of the polynomial 5x - 4x² + 3 at X = -2 is -23

Answer 2

Answer:

Let the given polynomial be f ( x ) .

f ( x ) = 5 x - 4 x² + 3

When x = 1

f ( 1 ) = 5 (1) - 4 (1)² + 3

⇒ f ( 1 ) = 5 - 4 + 3

⇒ f ( 1 ) =  1 + 3

⇒ f ( 1 ) = 4

The value will be 4.

When x = - 2

f ( - 2 ) = 5 (-2) - 4 (-2)² + 3

⇒ f ( - 2 ) = - 10 - 4 × 4 + 3

⇒ f ( - 2 ) = - 10 - 16 + 3

⇒ f ( - 2 ) = - 26 + 3

⇒ f ( - 2 ) = - 23

MORE INFO :

The polynomial is an expression of the form :

$ax^n+bx^{n-1}+...$