contestada

A square has a side length x cm and area A cm2.

The area is increasing at a constant rate of 0.03 cm2s-1.

Find the rate of increase of x when A=25.

(Please solve and explain?)

Respuesta :

Answer:

The rate of increase of x when A = 25 is 0.0006 cm/s.

Step-by-step explanation:

Area of a square A = [tex]x^{2}[/tex] sq. cm

So, x = [tex]\sqrt{A}[/tex] cm

[tex]\frac{dx}{dt} =\frac{1}{2\sqrt{A} } (\frac{dA}{dt} )[/tex] --- (1)

It is given that the area is increasing at the rate of 0.03 [tex]cm^{2}[/tex]/s.

Therefore,

[tex]\frac{dA}{dt} =0.03 cm^{2} /s[/tex]

We need to find the rate of increase of x when A = 25.

Now, substituting the values of A and [tex]\frac{dA}{dt}[/tex], (1) becomes

[tex]\frac{dx}{dt} =\frac{1}{2\sqrt{25} } (0.03)[/tex]

= 0.0006

Hence, the rate of increase of x when A = 25 is 0.0006 cm/s.