Question

The parametric equation of a line is given by $x=-2+\frac{r}{\sqrt{10}}$ and $y=1+3\frac{r}{\sqrt{10}}$. Then, for the line

• A. intercept on the $x-axis=\frac{7}{3}$
• B. intercept on the $y-axis=-7$
• C. slope of the line $=\frac{1}{3}$
• D. slope of the line $=3$

Answer 1

The correct option is D slope of the line $=3$

$x=-2+\frac{r}{\sqrt{10}}\Rightarrow \frac{r}{\sqrt{10}}=x+2$

$y=1+3\frac{r}{\sqrt{10}}$

$\Rightarrow y=1+3(x+2)$

$\Rightarrow y=3x+7$

$y=0,$ $x=-7/3$

$x=0$ $y=7$

Slope $=3$

Hence option D is correct