The slope of tangent to the curve $x=t^2+3 t-8, y=2 t^2-2 t-5$ at the point (2, -1) is: |
$\frac{22}{7}$ $\frac{-6}{7}$ $\frac{7}{6}$ $\frac{6}{7}$ |
$\frac{6}{7}$ |
The correct answer is Option (4) → $\frac{6}{7}$ $\frac{dx}{dt}=2t+3$, $\frac{dy}{dt}=4t-2$ $\frac{dy}{dx}=\frac{4t-2}{2t+3}$ at $x=2$ $2=t^2+3t-8$ $t^2+3t-10=0$ $t=2,-5$ so $t=2$ satisfies $y=-1$ so $\frac{dy}{dx}=\frac{4×2-2}{2×2+3}=\frac{6}{7}$ |