Question

f( x) 4x^2-1

a)
$\sqrt{2}$
​

Answer 1

f(x) = 4x² - 1

$\displaystyle \mathsf{f(\sqrt{2}) = 4( { \sqrt{2})}^{2} - 1} \\ \displaystyle \mathsf{}\displaystyle \mathsf{f(\sqrt{2}) = 4.2 - 1} \\ \mathsf{f(\sqrt{2}) = 8 - 1} \\ \mathsf{f( \sqrt{2}) = 7}$