Q34 / 90 · JEE Main 2010 · Mathematics
The equation of the tangent to the curve $y=x+\frac{4}{x^2}$, that is parallel to the $x$-axis, is
- A$y=1$
- B$y=2$
- Correct answerC$y=3$
- D$y=0$
Solution
Parallel to $x$-axis $\quad \Rightarrow \frac{d y}{d x}=0 \quad \Rightarrow 1-\frac{8}{x^3}=0$ $\Rightarrow x=2 \quad \Rightarrow y=3$
Equation of tangent is $y-3=0(x-2) \quad \Rightarrow y-3=0$
Hence, the correct answer is option: 'C'.