Q. Let y4+5x=11.What is the value of dx2d2y at the point (2,1) ?Give an exact number.
Differentiate Equation: Given the equation y4+5x=11, we need to find the second derivative of y with respect to x, dx2d2y, at the point (2,1). To do this, we first need to differentiate both sides of the equation with respect to x to find the first derivative dxdy. Differentiate y4+5x=11 with respect to x: dxd(y4)+dxd(5x)=dxd(11) Using the power rule and the constant rule for differentiation, we get: y0
Solve for dxdy: Now we need to solve for dxdy:4y3⋅dxdy+5=0 Subtract 5 from both sides:4y3⋅dxdy=−5 Divide both sides by 4y3:dxdy=4y3−5
Find Second Derivative: Next, we need to find the second derivative (d2y)/(dx2). To do this, we differentiate (dy/dx) with respect to x again. However, since dy/dx is a function of y, and y is a function of x, we need to use the chain rule for differentiation.Differentiate (dy/dx)=−5/(4y3) with respect to x:(d2y)/(dx2)=d/dx(−5/(4y3))Using the chain rule and the power rule, we get:(dy/dx)0(dy/dx)1(dy/dx)2
Substitute dxdy: Now we need to substitute the expression we found for dxdy into the equation for the second derivative:dx2d2y=15×(4y41)×(−4y35)Simplify the expression:dx2d2y=15×(−5)/(16y7)dx2d2y=−16y775
Evaluate at (2,1): Finally, we need to evaluate the second derivative at the point (2,1). Since y=1 at this point, we substitute y=1 into the expression for the second derivative:dx2d2y at (2,1) = −16⋅(1)775Simplify the expression:dx2d2y at (2,1) = −1675
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