A) (2, 4)
B) (2, -4)
C) \[\left( \frac{-9}{8},\frac{9}{2} \right)\]
D) \[\left( \frac{9}{8},\frac{9}{2} \right)\]
Correct Answer: D
Solution :
[d] The equation of the parabola is\[{{y}^{2}}=18x\]. Differentiating w.r.t. t, we get \[2y\frac{dy}{dt}=18\frac{dx}{dt}\] \[\Rightarrow 2\times 2y=18\] \[\left( \therefore \frac{dy}{dt}=2\frac{dx}{dt} \right)\] \[\Rightarrow y=\frac{9}{2}\] From the equation of the parabola, we get \[{{\left( \frac{9}{2} \right)}^{2}}=18x\] \[\Rightarrow \frac{81}{4}=18x\] \[\Rightarrow x=\frac{81}{4\times 18}\] \[\Rightarrow x=\frac{9}{8}\] Hence, the point is\[(9\text{/}8,\,\,\,9\text{/}2)\].
You need to login to perform this action.
You will be redirected in
3 sec
