A curve has equation y = x^5– 8x^3+16x. The normal at the point P(1,9) and the tangent at the point Q(-1, -9) intersect at the point R.
Find the coordinates of R.

Pls help

Respuesta :

Answer:

R(-6.2;6.6)

Step-by-step explanation:

(for more info see the attached picture and graph)

1) to find the equation of the tangent at the point P(1;9);

2) to find the equation of the normal at the point P(1;9) using the tangent found before;

3) to find the equation of the tangent at the point Q(-1;-9);

4) to make up the system of two equations (items 2 and 3) and solve it.

P.S. note, the suggested way is not the shortest one;

P.P.S. change design according Your requirements.

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The coordinates of point R are [tex](x,y) = \left(-\frac{31}{5} ,\frac{33}{5} \right)[/tex].

How to determine the point of intersection of a system of equations

In this exercise we must determine the equation of the normal and tangent lines before finding out the point of intersection. By calculus we know that slope of the line tangent to a point of the curve ([tex]m[/tex]) is equal to the first derivative of the function evaluated at that point.

[tex]m = 5\cdot x^{4}-24\cdot x^{2}+16[/tex] (1)

In addition, the slope of the line normal to the curve ([tex]m_{\perp}[/tex]) is determined by following geometric expression:

[tex]m_{\perp} = -\frac{1}{m}[/tex] (2)

Then, we proceed to determine the linear equations:

Point P ([tex]P(x,y) = (1,9)[/tex])

[tex]m = 5\cdot (1)^{4}-24\cdot (1)^{2}+16[/tex]

[tex]m = -3[/tex]

[tex]m_{\perp} = \frac{1}{3}[/tex]

And the intercept of the function is:

[tex]b = y-m\cdot x[/tex]

[tex]b = 9-\left(\frac{1}{3} \right)\cdot (1)[/tex]

[tex]b = \frac{26}{3}[/tex]

Point Q ([tex]Q(x,y) = (-1,-9)[/tex])

[tex]m = 5\cdot (-1)^{4}-24\cdot (-1)^{2}+16[/tex]

[tex]m = -3[/tex]

And the intercept of the function is:

[tex]b = y-m\cdot x[/tex]

[tex]b = -9-\left(-3 \right)\cdot (-1)[/tex]

[tex]b = -12[/tex]

The system of equations is represented by following two expressions:

[tex]y = \frac{1}{3}\cdot x +\frac{26}{3}[/tex] (3)

[tex]y=-3\cdot x -12[/tex] (4)

Then, the coordinates of point R are [tex](x,y) = \left(-\frac{31}{5} ,\frac{33}{5} \right)[/tex]. [tex]\blacksquare[/tex]

To learn more on systems of equations, we kindly invite to check this verified question: https://brainly.com/question/20379472

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