(a) find the points on the graph of $y^{2}=x^{3}-3x + 1$ where the tangent line is horizontal.

(a) find the points on the graph of $y^{2}=x^{3}-3x + 1$ where the tangent line is horizontal.

(a) find the points on the graph of $y^{2}=x^{3}-3x + 1$ where the tangent line is horizontal.

Answer

Explanation:

Step1: Differentiate implicitly

Differentiate $y^{2}=x^{3}-3x + 1$ with respect to $x$. Using the chain - rule on the left - hand side and power rule on the right - hand side. $2y\frac{dy}{dx}=3x^{2}-3$.

Step2: Solve for $\frac{dy}{dx}$

$\frac{dy}{dx}=\frac{3x^{2}-3}{2y}$.

Step3: Set $\frac{dy}{dx}=0$

For a horizontal tangent line, $\frac{dy}{dx} = 0$. So we set $3x^{2}-3 = 0$. $3x^{2}-3=0$ implies $x^{2}=1$, so $x=\pm1$.

Step4: Find the corresponding $y$ values

When $x = 1$: $y^{2}=1^{3}-3\times1 + 1=1 - 3+1=-1$. Since $y^{2}=-1$ has no real solutions, we discard $x = 1$. When $x=-1$: $y^{2}=(-1)^{3}-3\times(-1)+1=-1 + 3+1=3$. So $y=\pm\sqrt{3}$.

Answer:

The points are $(-1,\sqrt{3})$ and $(-1,-\sqrt{3})$.