Q. If 4x−4−4x2=y2−y3 then find dxdy at the point (1,2).Answer: dxdy∣∣(1,2)=
Differentiate and Simplify: First, we need to differentiate both sides of the equation with respect to x to find dxdy. The equation is 4x−4−4x2=y2−y3. Differentiating the left side with respect to x gives us the derivative of 4x, which is 4, minus the derivative of 4, which is 0, minus the derivative of 4x2, which is 8x. Differentiating the right side with respect to x is a bit more complex because it involves dxdy1, which is a function of x. We need to use the chain rule. The derivative of dxdy3 with respect to x is dxdy5, and the derivative of dxdy6 with respect to x is dxdy8. So, the differentiated equation is dxdy9.
Solve for dxdy: Now we need to solve for dxdy. We can factor out dxdy on the right side of the equation to get dxdy(2y−3y2). So, we have 4−8x=dxdy(2y−3y2). To solve for dxdy, we divide both sides by (2y−3y2). This gives us dxdy=2y−3y24−8x.
Substitute Point and Calculate: Next, we need to substitute the point (1,2) into the equation to find the value of dxdy at that point.Substituting x=1 and y=2 into the equation dxdy=(2y−3y2)(4−8x) gives us dxdy=(2⋅2−3⋅22)(4−8⋅1).
Perform Calculations: Now we perform the calculations.Calculating the numerator: 4−8×1=4−8=−4.Calculating the denominator: 2×2−3×22=4−3×4=4−12=−8.So, dxdy=−8−4.
Simplify Fraction: Finally, we simplify the fraction−84 to get the value of dxdy. Simplifying the fraction gives us dxdy=21. Therefore, the value of dxdy at the point (1,2) is 21.