Question

HELP WITH RELATED RATES

Answer 1

CAN SOMEONE PLEASE CLARIFY TO ME THE 3RD STEP...?

Answer 2

what is the question?
the start with
[ x^2+y^2= 4 \]
they use implicit differentiation
\[ \frac{d}{dt}\left(x^2+y^2= 4\right) \\
\frac{d}{dt}x^2 + \frac{d}{dt}y^2 = \frac{d}{dt}4 \\
2x \frac{dx}{dt}+2y \frac{dy}{dt}=0\\
x \frac{dx}{dt} + y \frac{dy}{dt}=0
\]

Answer 3

now the solve for dx/dt. First add -y dy/dt to both sides
\[ x \frac{dx}{dt} = -y \frac{dy}{dt} \]
divide both sides by x
\[ \frac{dx}{dt}= \frac{-y}{x} \frac{dy}{dt}\]

now substitute in for y, x and dy/dt (given in the problem )