Brief Calculus.

Question

Find dx/dt at x = 5 if y = -x² + 4 and dy/dt = 1.

dx/dt = .........................

Answer 1

dy/dt = -2xdx/dt; dx/dt = (dy/dt)/(- 2x) = 1/(- 2·5) = - 0.1

Answer 2

x' = - a tenth

y' = -2xx'

y'=1 x=5,