Find an equation of the tangent to the curve at the given point by both eliminating the parameter and without eliminating the parameter. x = 5 + ln(t), y = t2 + 2, (5, 3)

Respuesta :

Answer:

Step-by-step explanation:

Given that:

[tex]x = 5 + In (t)[/tex]

[tex]y = t^2+2[/tex]

At point (5,3)

To find an equation of the tangent to the curve at the given point,

By without eliminating the parameter

[tex]\dfrac{dx}{dt}= \dfrac{1}{t}[/tex]

[tex]\dfrac{dy}{dt}= 2t[/tex]

[tex]\dfrac{dy}{dx}= \dfrac{ \dfrac{dy}{dt} }{\dfrac{dx}{dt} }[/tex]

[tex]\dfrac{dy}{dx}= \dfrac{ 2t }{\dfrac{1}{t} }[/tex]

[tex]\dfrac{dy}{dx}= 2t^2[/tex]

[tex]\dfrac{dy}{dx}_{ (5,3)}= 2t^2_{ (5,3)}[/tex]

t²  + 5 = 4

t² = 4 - 5

t² = - 1

Then;

[tex]\dfrac{dy}{dx}_{ (5,3)}= -2[/tex]

The equation of the tangent  is:

[tex]y -y_1 = m(x-x_1)[/tex]

[tex](y-3 )= -2(x - 5)[/tex]

y - 3 = -2x +10

y = -2x + 7

y = 2x - 7

By eliminating the parameter

x = 5 + In(t)

In(t)  = 5 - x

[tex]t =e^{x-5}[/tex]

[tex]y = (e^{x-5})^2+5[/tex][tex]y = (e^{2x-10})+5[/tex]

[tex]\dfrac{dy}{dx} = 2e^{2x-10}[/tex]

[tex]\dfrac{dy}{dx}_{(5,3)} = 2e^{10-10}[/tex]

[tex]\dfrac{dy}{dx}_{(5,3)} = 2[/tex]

The equation of the tangent  is:

[tex]y -y_1 = m(x-x_1)[/tex]

[tex](y-3 )= -2(x - 5)[/tex]

y - 3 = -2x +10

y = -2x + 7

y = 2x - 7