How do you find the first and second derivatives of the functions defined as x = cos²(t) and y = cos(t) over the interval 0 ≤ t ≤ π?

To find the first and second derivatives of the functions defined by x = cos²(t) and y = cos(t), we will start by applying differentiation rules known as the chain rule and product rule in calculus.

Step 1: Finding the first derivative:

For x = cos²(t), we will differentiate using the chain rule:

dx/dt = 2*cos(t)*(-sin(t)) = -2*cos(t)*sin(t)

For y = cos(t), differentiating gives:

dy/dt = -sin(t)

Step 2: Equating dy/dx:

Now, we can find dy/dx using the formula:

dy/dx = (dy/dt)/(dx/dt) = (-sin(t))/(-2*cos(t)*sin(t)) = 1/(2*cos(t))

Step 3: Finding the second derivative:

The second derivative can be found by differentiating dy/dx again with respect to t:

d²y/dx² = d/dt(1/(2*cos(t))) = (-1/2) * (0 - sin(t)*(-1))/(cos²(t)) = sin(t)/(2*cos²(t))

Now we have:

  • First Derivative: dy/dx = 1/(2*cos(t))
  • Second Derivative: d²y/dx² = sin(t)/(2*cos²(t))

Conclusion: Therefore, for the functions defined above, the first and second derivatives over the interval 0 ≤ t ≤ π are given by the expressions derived. You can substitute specific values of t within that interval if you need numerical results.

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