Solving Related Rates Problems, Derivative, Ladder Problem - Calculus

This calculus video provides a worked example on solving related rates problems using derivatives.

[getsetgaming]

After differentiation, where did that extra dx/dt and dy/dt came from along with 2x and 2y

[KarylLatosa]

How did you get 1.3? It's not exactly 1.3 actually, so you could arrive at wrong value/answer?

[raphaelgomes]

I got 4.333... m/s. How did you get 4.4?

[OWASIA]

You got the value of y from Pythagoras formula.i got that.but why you used -ve sign with dy/dt ?

[nickschneider]

I solved Pythagorean theorem for y to get dy/dt = (4-x^2)^(1/2) d/dx dx/dt
Your way is simpler