Math Problem Statement

what is the equation of the tangent line at (pi^2, pi)

What is the equation of the tangent line at (π^2, π) on the curve 3 sin(y) + x = y^2?

Solution

To find the equation of the tangent line at the given point (π2,π)(\pi^2, \pi) for the curve 3siny+x=y23 \sin y + x = y^2, we will follow these steps:

1. Verify the point lies on the curve:

The point is (π2,π)(\pi^2, \pi). We substitute x=π2x = \pi^2 and y=πy = \pi into the given equation:

3sin(π)+π2=π2.3 \sin(\pi) + \pi^2 = \pi^2.

Since sin(π)=0\sin(\pi) = 0, this simplifies to:

0+π2=π2,0 + \pi^2 = \pi^2,

which is true, so the point (π2,π)(\pi^2, \pi) does lie on the curve.

2. Implicit Differentiation:

We need to find the slope of the tangent line by differentiating the given equation implicitly:

3siny+x=y2.3 \sin y + x = y^2.

Taking the derivative with respect to xx on both sides:

ddx(3siny)+ddx(x)=ddx(y2),\frac{d}{dx}(3 \sin y) + \frac{d}{dx}(x) = \frac{d}{dx}(y^2),

which becomes:

3cosydydx+1=2ydydx.3 \cos y \cdot \frac{dy}{dx} + 1 = 2y \cdot \frac{dy}{dx}.

Now, solve for dydx\frac{dy}{dx} (which is the slope of the tangent line):

3cosydydx+1=2ydydx.3 \cos y \cdot \frac{dy}{dx} + 1 = 2y \cdot \frac{dy}{dx}.

Group the dydx\frac{dy}{dx} terms together:

dydx(3cosy2y)=1.\frac{dy}{dx}(3 \cos y - 2y) = -1.

Thus, the slope is:

dydx=13cosy2y.\frac{dy}{dx} = \frac{-1}{3 \cos y - 2y}.

3. Evaluate the slope at y=πy = \pi:

Substitute y=πy = \pi into the slope equation:

dydx=13cos(π)2π.\frac{dy}{dx} = \frac{-1}{3 \cos(\pi) - 2\pi}.

Since cos(π)=1\cos(\pi) = -1, this simplifies to:

dydx=13(1)2π=132π=13+2π.\frac{dy}{dx} = \frac{-1}{3(-1) - 2\pi} = \frac{-1}{-3 - 2\pi} = \frac{1}{3 + 2\pi}.

4. Equation of the Tangent Line:

The tangent line at (π2,π)(\pi^2, \pi) has the form:

yy1=m(xx1),y - y_1 = m(x - x_1),

where m=13+2πm = \frac{1}{3 + 2\pi}, x1=π2x_1 = \pi^2, and y1=πy_1 = \pi.

Substitute these values into the equation:

yπ=13+2π(xπ2).y - \pi = \frac{1}{3 + 2\pi}(x - \pi^2).

Finally, solving for yy in slope-intercept form:

y=13+2π(xπ2)+π.y = \frac{1}{3 + 2\pi}(x - \pi^2) + \pi.

This is the equation of the tangent line at (π2,π)(\pi^2, \pi).


Let me know if you'd like further clarifications or details!

Here are five related questions for further practice:

  1. How would the equation of the tangent line change if the point were (4,2)(4, 2) on the same curve?
  2. How do you verify that a point lies on a curve in general?
  3. What is the geometric meaning of the derivative in the context of tangent lines?
  4. Can you find the second derivative d2ydx2\frac{d^2y}{dx^2} at (π2,π)(\pi^2, \pi)?
  5. How does implicit differentiation differ from explicit differentiation?

Tip: When dealing with implicit functions, always remember to apply the chain rule when differentiating terms that involve the dependent variable!

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Implicit Differentiation
Trigonometry
Calculus
Tangent Lines

Formulas

Implicit Differentiation: d/dx(f(y)) = f'(y) * dy/dx
Tangent Line Equation: y - y1 = m(x - x1)

Theorems

Chain Rule
Slope of a Tangent Line

Suitable Grade Level

College-level Calculus or Advanced High School Calculus