## anonymous one year ago anyone who can answer this? a point moves on the parabola y^2=8 in such a way that the rate of change of the ordinate is always 5 units/second. how fast is the abscissa changing when the ordinate is 4?

1. ganeshie8

ordinate : y coordinate abscissa : x coordinate

2. ganeshie8

could you double check the equation of parabola, is it really y^2=8 ?

3. anonymous

yes it is y^2=8

4. anonymous

i also think that the questions seems lacking, or something wrong?

5. ganeshie8

im pretty sure the equation is y^2=8$$\color{red}{x}$$

6. ganeshie8

y^2 = 8 does not produce a parabola when you graph

7. anonymous

yes..

8. anonymous

i also think that way..

9. ganeshie8

good, lets make it y^2=8x

10. ganeshie8

we're given $$\dfrac{dy}{dt}=5$$

11. ganeshie8

$y^2=8x$ differentiate both sides with respect to $$t$$

12. anonymous

$2y \frac{ dy }{ dt} = 8\frac{ dx }{ dt }$

13. anonymous

is that right?

14. ganeshie8

Yes, plugin the given values

15. anonymous

i got it

16. anonymous

$\frac{ dx }{ dt} = 5$

17. anonymous

thanks sir

18. ganeshie8

Yw!