Đáp án:
$\begin{array}{l}
f\left( x \right) = 2{x^2} - 3x + 5\\
\Delta y = f\left( {{x_0} + \Delta x} \right) - f\left( {{x_0}} \right)\\
a)\Delta y = f\left( {{x_0} + \Delta x} \right) - f\left( {{x_0}} \right)\\
= f\left( 2 \right) - f\left( 1 \right)\\
= 7 - 4 = 3\\
b)\Delta y = f\left( {0,9} \right) - f\left( 2 \right)\\
= 3,92 - 7 = 3,08\\
c)\Delta y = f\left( 1 \right) - f\left( 0 \right)\\
= 4 - 5 = - 1\\
d)\Delta y = f\left( 2 \right) - f\left( 0 \right)\\
= 7 - 5 = 2
\end{array}$