MCQ
If $f'(x) = \frac{1}{x} + x$ and $f(1) = \frac{5}{2}$, then $f(x) = $
  • $\log x + \frac{{{x^2}}}{2} + 2$
  • B
    $\log x + \frac{{{x^2}}}{2} + 1$
  • C
    $\log x - \frac{{{x^2}}}{2} + 2$
  • D
    $\log x - \frac{{{x^2}}}{2} + 1$

Answer

Correct option: A.
$\log x + \frac{{{x^2}}}{2} + 2$
a
(a) $f(x) = \int_{}^{} {f'(x)\,dx} = \int_{}^{} {\left( {\frac{1}{x} + x} \right)} \,dx = \log x + \frac{{{x^2}}}{2} + c$
Put $x = 1,$ then $\frac{5}{2} = 0 + \frac{1}{2} + c \Rightarrow c = 2$
Therefore, $f(x) = \log x + \frac{{{x^2}}}{2} + 2.$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

If $x^2-y^2+2 h x y+2 g x+2 f y+c=0$ is the locus of a point, which moves such that it is always equidistant from the lines $x+2 y+7=0$ and $2 x-y$ $+8=0$, then the value of $\mathrm{g}+\mathrm{c}+\mathrm{h}-\mathrm{f}$ equals
The angle between the lines whose intercepts on the axes are $a, -b$ and $b, -a $ respectively, is
A value of $\theta  \in  (0, \pi /3)$, for which $\left| {\begin{array}{*{20}{c}}
  {1 + {{\cos }^2}\,\theta }&{{{\sin }^2}\,\theta }&{4\,\cos \,6\theta } \\ 
  {{{\cos }^2}\,\theta }&{1 + {{\sin }^2}\,\theta }&{4\,\cos \,6\theta } \\ 
  {{{\cos }^2}\,\theta }&{{{\sin }^2}\,\theta }&{1 + 4\,\cos \,6\theta } 
\end{array}} \right| = 0$, is
The area bounded by the curve $y=\cos x$, the line joining $(-\pi / 4, \cos (-\pi / 4))$ and $(0,2)$ and the line joining $(\pi / 4, \cos (\pi / 4))$ and $(0,2)$ is
Let $\mathrm{X}$ be the set of all five digit numbers formed using $1,2,2,2,4,4,0$. For example, $22240$ is in $\mathrm{X}$ while $02244$ and $44422$ are not in $X$. Suppose that each element of $X$ has an equal chance of being chosen. Let $\mathrm{p}$ be the conditional probability that an element chosen at random is a multiple of $20$ given that it is a multiple of $5$ . Then the value of $38 p $ is equal to
Which of the following equation is non-linear
If ${\Delta _1} = \left| {\,\begin{array}{*{20}{c}}x&b&b\\a&x&b\\a&a&x\end{array}\,} \right|$ and ${\Delta _2} = \left| {\,\begin{array}{*{20}{c}}x&b\\a&x\end{array}\,} \right|$ are the given determinants, then
Let $S$ be the region bounded by the curves $y=x^{3}$ and $y ^{2}= x$. The curve $y =2| x |$ divides $S$ into two regions of areas $R_{1}$ and $R_{2}$.

If $\max \left\{R_{1}, R_{2}\right\}=R_{2}$, then $\frac{R_{2}}{R_{1}}$ is equal to

If a line makes angles of ${30^o}$ and ${45^o}$ with $x$ - axis and $y$ - axis, then the angle made by it with $z$ - axis is
Equation of the normal to the hyperbola $\frac{{{x^2}}}{{25}} - \frac{{{y^2}}}{{16}} = 1$ perpendicular to the line $2x + y = 1$ is