<em>Hope</em><em> </em><em>this</em><em> </em><em>will</em><em> </em><em>help</em><em> </em><em>u</em><em>.</em><em>.</em><em>✌</em><em />
See the attached figures.
The area of this trapezoid = 576
cm²
Dy/dx = dy/dt / dx/dt
dy/dx = 12x^2 + 4
when x = 2 , dydx = 52
52 = dy/dt / 3
so dy/dt = 156 (answer)
S is slope
S= rise/run
S1=3/12=1/4
S2=2/16=1/8
S3=5/15=1/3
S4=4/20=1/5
Deepest slope S3 aka C