find the tangent line equation at x=cost+sin2t, y=sint+cos2t, t=0

User Icon for Damon Damon answered
7 years ago

y = sin t + cos^2 t - sin^2 t

dy/dt = cos t -2cost sint -2 sint cost
at t = 0 dy/dt = 1

x = cos t +2 sin t cos t
dx/dt = -sint -2sin^2t+2 cos^2t
at t = 0 dx/dt = 2

dy/dt / dx/dt = 1/2 = slope

x = 1 and y = 1 at t = 0
y = 1 x + b
b = 0
y = x

User Icon for Damon Damon answered
7 years ago

x = 1 and y = 1 at t = 0

y = .5 x + b
1 = .5 + b
b = .5
y = .5 x + .5

User Icon for Lielle Lielle answered
7 years ago

the 2s aren't exponents, is the process the same?

User Icon for Explain Bot Explain Bot answered
11 months ago

To find the equation of the tangent line at a specific point on a curve, you need to determine the slope of the curve at that point.

Given the parametric equations x = cos(t) + sin(2t) and y = sin(t) + cos(2t), we can find the tangent line equation at t = 0 by following these steps:

1. Calculate the derivatives dx/dt and dy/dt.

The derivative of x with respect to t, dx/dt, represents the rate of change of x with respect to t. Similarly, the derivative of y with respect to t, dy/dt, represents the rate of change of y with respect to t.

dx/dt = -sin(t) + 2cos(2t)
dy/dt = cos(t) - 2sin(2t)

2. Evaluate the derivatives at t = 0.

Substituting t = 0 into the derivatives, we get:

dx/dt = -sin(0) + 2cos(0) = -1 + 2 = 1
dy/dt = cos(0) - 2sin(0) = 1 - 0 = 1

So, at t = 0, dx/dt = 1 and dy/dt = 1.

3. Use the derivatives to calculate the slope of the tangent line.

The slope of the tangent line is given by the derivative of y with respect to x, which is dy/dx. We can calculate dy/dx using the formula:

dy/dx = (dy/dt) / (dx/dt)

Substituting the values we found earlier:

dy/dx = 1 / 1 = 1

Therefore, the slope of the tangent line at t = 0 is 1.

4. Find the coordinates of the point on the curve at t = 0.

Substituting t = 0 into the given parametric equations, we get:

x = cos(0) + sin(2(0)) = 1 + sin(0) = 1 + 0 = 1
y = sin(0) + cos(2(0)) = sin(0) + cos(0) = 0 + 1 = 1

So, the point on the curve at t = 0 is (1, 1).

5. Write the equation of the tangent line.

We now have the slope of the tangent line (m = 1) and the point on the curve (1, 1). Using the point-slope form of a linear equation:

y - y1 = m(x - x1)

Substituting the values:

y - 1 = 1(x - 1)

Simplifying:

y - 1 = x - 1
y = x

Hence, the equation of the tangent line at x = cos(t) + sin(2t), y = sin(t) + cos(2t), t = 0 is y = x.