Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Definite Integration

Question:

If $\frac{d}{dx}f(x)=4x^3-3/x^4$ such that $f(2)=0$. Then $f(x)$ is

Options:

$x^3+1/x^4-129/8$

$x^4+x^3-129/8$

$x^4+1/x^3-125/8$

$x^4+1/x^3-129/8$

Correct Answer:

$x^4+1/x^3-129/8$

Explanation:

The anti derivative of $4x^3-3/x^4$ is $f(x)$. Hence$$f(x)=\int(4x^3-3/x^4)dx$$. Integrating this function we get $f(x)=x^4+1/x^3+C$ and substituting $f(2)=0$ we get the integration constant $C=-129/8$. Hence the result.