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Slope of the Tangent to Curve at Specified Point

Determine the slope of the tangent to the curve (y−x5)2=x(1+x2)2(y - x^5)^2 = x(1 + x^2)^2 evaluated at the point (1,3)(1, 3).

Official Numerical Answer8

Step-by-Step Solution

To find the slope of the tangent to the curve (y−x5)2=x(1+x2)2(y - x^5)^2 = x(1 + x^2)^2 at the point (1,3)(1, 3), we need to determine the value of dydx\frac{dy}{dx} at (x,y)=(1,3)(x, y) = (1, 3).

First, verify that the point (1,3)(1, 3) lies on the curve: LHS=(3−15)2=(2)2=4\text{LHS} = (3 - 1^5)^2 = (2)^2 = 4 RHS=1⋅(1+12)2=1⋅(2)2=4\text{RHS} = 1 \cdot (1 + 1^2)^2 = 1 \cdot (2)^2 = 4 Since LHS=RHS\text{LHS} = \text{RHS}, the point (1,3)(1, 3) lies on the curve.

Now, differentiate both sides of the given implicit equation with respect to xx: ddx[(y−x5)2]=ddx[x(1+x2)2]\frac{d}{dx} \left[ (y - x^5)^2 \right] = \frac{d}{dx} \left[ x(1 + x^2)^2 \right]

Applying the chain rule to the left-hand side and the product rule along with the chain rule to the right-hand side gives: 2(y−x5)⋅(dydx−5x4)=(1+x2)2⋅ddx(x)+x⋅ddx[(1+x2)2]2(y - x^5) \cdot \left( \frac{dy}{dx} - 5x^4 \right) = (1 + x^2)^2 \cdot \frac{d}{dx}(x) + x \cdot \frac{d}{dx} \left[ (1 + x^2)^2 \right]

2(y−x5)(dydx−5x4)=(1+x2)2+x⋅2(1+x2)(2x)2(y - x^5)\left( \frac{dy}{dx} - 5x^4 \right) = (1 + x^2)^2 + x \cdot 2(1 + x^2)(2x)

Simplifying the right-hand side: 2(y−x5)(dydx−5x4)=(1+x2)2+4x2(1+x2)2(y - x^5)\left( \frac{dy}{dx} - 5x^4 \right) = (1 + x^2)^2 + 4x^2(1 + x^2)

(1+x2)[(1+x2)+4x2]=(1+x2)(1+5x2)(1 + x^2)\Big[ (1 + x^2) + 4x^2 \Big] = (1 + x^2)(1 + 5x^2)

Thus, the differentiated equation is: 2(y−x5)(dydx−5x4)=(1+x2)(1+5x2)2(y - x^5)\left( \frac{dy}{dx} - 5x^4 \right) = (1 + x^2)(1 + 5x^2)

Substitute x=1x = 1 and y=3y = 3 into this equation: 2(3−15)(dydx∣(1,3)−5(1)4)=(1+12)(1+5(1)2)2(3 - 1^5) \left( \left. \frac{dy}{dx} \right|_{(1,3)} - 5(1)^4 \right) = (1 + 1^2)(1 + 5(1)^2)

2(2)(dydx∣(1,3)−5)=(2)(6)2(2) \left( \left. \frac{dy}{dx} \right|_{(1,3)} - 5 \right) = (2)(6)

4(dydx∣(1,3)−5)=124 \left( \left. \frac{dy}{dx} \right|_{(1,3)} - 5 \right) = 12

Divide both sides by 44: dydx∣(1,3)−5=3\left. \frac{dy}{dx} \right|_{(1,3)} - 5 = 3

dydx∣(1,3)=8\left. \frac{dy}{dx} \right|_{(1,3)} = 8

The slope of the tangent to the curve at the point (1,3)(1, 3) is 88.