Question

Let \(y=f(x)=2 x^{2}-3 x+2\). The differential of \(y\) when \(x\) changes from 2 to \(1.99\) is
(A) \(0.01\)
(B) \(0.18\)
(C) \(-0.05\)
(D) \(0.07\)

Answer 1

Ans: (C)
Hint : \(\Delta x=-0.01 \Rightarrow \Delta y=f^{\prime}(x) \Delta x \Rightarrow \Delta y=f^{\prime}(2)(-0.01) \Rightarrow \Delta y=-5 \times 0.01 \Rightarrow \Delta y=-0.05\)