Question

Y^2 = 7x + 1. Also,dx/dt =-3. find dy/dt when y=6

Answer 1

`( - 7)/(4)`

1. dy/dx=dy/dt ×dt/dx
2. dy/dt= dy/dx × dx/dt
3. y²=7x+1
4. 2ydy/dx=7
5. dy/dx=7/2y
6. where y=6
7. dy/dx=7/2(6)
8. dy/dx=7/12
9. from,dy/dt =dy/dx ×dx/dt
10. where, dx/dt = -3
11. dy/dt =7/12 ×(-3)
12. dy/dt = -7/4