Question

Find the value of; 2x³ - 3x + V5 when x = -3​

Answer 1

$\textbf{Given:}$

$2\,x^3-3\,x+\sqrt{5}$

$\textbf{To find:}$

$\text{The value of 2\,x^3-3\,x+\sqrt{5} when x=-3 }$

$\textbf{Solution:}$

$\text{Let}\;P(x)=2\,x^3-3\,x+\sqrt{5}$

$\text{Consider,}$

$P(-3)$

$=2(-3)^3-3(-3)+\sqrt{5}$

$=2(-27)+9+\sqrt{5}$

$=-54+9+\sqrt{5}$

$=-45+\sqrt{5}$

$=\sqrt{5}-45$

$\textbf{Answer:}$

$\textbf{The value of \bf\,2\,x^3-3\,x+\sqrt{5} when \bf\,x=-3 is \bf\,\sqrt{5}-45 }$