Practicing Success
Let $f(t)=\ln (t)$. Then, $\frac{d}{d x}\left(\int\limits_{x^2}^{x^3} f(t) d t\right)$. Which one of the above is incorrect? |
has value 0 when $x=0$ has value 0 when $x=1$ and $x=4 / 9$ has value $9 e^2-4 e$ when $x=e$ has differential coefficient $27 e-8$ for $x=e$ |
has value 0 when $x=0$ |
Let $F(x)=\frac{d}{d x}\left(\int\limits_{x^2}^{x^3} \ln (t) d t\right)$ $\Rightarrow F'(x) =3 x^2 \log x^3-2 x \log x^2$ [Using Leibnitz's Rule] $\Rightarrow F'(x) =9 x^2 \log x-4 x \log x=\left(9 x^2-4 x\right) \log x$ ∴ $F'(x)=(9 x-4)+(18 x-4) \log x$ Clearly, F(x) and F'(x) satisfy (b), (c) and (d) respectively. Hence, option (a) is incorrect. |