Step-by-step explanation:
Let l be one side,w be other side and s be diagonal.
We have
s² = l² + w²
We have
l = 8 cm
w = 6 cm
s² = l² + w²
s² = 8² + 6²
s² = 100
s = 10 cm
Taking derivative with respect to time in s² = l² + w²
[tex]s^2=l^2+w^2\\\\2s\frac{ds}{dt}=2l\frac{dl}{dt}+2w\frac{dw}{dt}\\\\s\frac{ds}{dt}=l\frac{dl}{dt}+w\frac{dw}{dt}\\\\\frac{dw}{dt}=3cm/min\\\\\frac{dl}{dt}=0cm/min\\\\10\frac{ds}{dt}=8\times 0+6\times 3\\\\\frac{ds}{dt}=1.8cm/min[/tex]
The diagonal is increasing at 1.8 cm/minute.
