Q. Let x3+y2=24.What is the value of dx2d2y at the point (2,4) ?Give an exact number.
Implicit Differentiation: Given the equation x3+y2=24, we need to find the second derivative of y with respect to x at the point (2,4). To do this, we first need to find the first derivative dxdy by implicit differentiation.Differentiate both sides of the equation with respect to x:dxd(x3)+dxd(y2)=dxd(24)3x2+2ydxdy=0Now, solve for dxdy:2ydxdy=−3x2y0
Second Derivative Calculation: Next, we need to find the second derivative dx2d2y. To do this, we differentiate dxdy with respect to x again, using implicit differentiation and the chain rule.Differentiate −2y3x2 with respect to x:dxd(dxdy)=dxd(−2y3x2)Using the quotient rule, we get:dx2d2y=(2y)2(2y⋅dxd(−3x2)−(−3x2)⋅dxd(2y))dx2d2y=(2y)2(2y⋅(−6x)−(−3x2)⋅2(dxdy))
Substitution of Values: Now we need to substitute dxdy from the first derivative we found earlier into the second derivative equation.Substitute dxdy=2y−3x2 into the second derivative:dx2d2y=(2y)2(2y⋅(−6x)−(−3x2)⋅2(−3x2/(2y)))Simplify the equation:dx2d2y=(4y2)(−12xy+9x4/y)
Final Result: Finally, we substitute the point (2,4) into the second derivative to find the value of dx2d2y at that point.Substitute x=2 and y=4 into the second derivative:dx2d2y=4⋅42(−12⋅2⋅4+9⋅24)/4Simplify the equation:dx2d2y=64(−96+144/4)dx2d2y=64(−96+36)dx2d2y=64−60Reduce the fraction:dx2d2y=16−15
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