If 5x2 + y4 = 21 then evaluate the second derivative of y with respect to x when x = 2 and y = 1. round your answer to two decimal places. use the hyphen symbol, -, for negative values.

-77.50

Step-by-step explanation:

We take first derivative

Derivative of x is 1. Derivative of y is dy/dx

Derivative of x^2 is 2x

Derivative of y^4 is 4y^3(dy/dx)

Now isolate dy/dx

Subtract 10x on both sides

Divide both sides by 4y^3

Now we take second derivative. Apply quotient rule

Derivative of -5x is -5 and derivative of 2y^3 is 6y(dy/dx)

Replace dy/dx ,

Now plug in x=2  and y=1