Find Equations For The Tangent And Normal Lines To $x \sin 2y = Y \cos 2x$ At \[$\left(\frac{\pi}{4}, \frac{\pi}{2}\right)\$\].

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Introduction

In this article, we will find the equations for the tangent and normal lines to the given curve xsin⁑2y=ycos⁑2xx \sin 2y = y \cos 2x at the point (Ο€4,Ο€2)\left(\frac{\pi}{4}, \frac{\pi}{2}\right). To do this, we will first find the derivative of the curve using implicit differentiation. Then, we will use the derivative to find the slope of the tangent line at the given point. Finally, we will use the slope of the tangent line to find the equation of the tangent line and the normal line.

Implicit Differentiation

To find the derivative of the curve xsin⁑2y=ycos⁑2xx \sin 2y = y \cos 2x, we will use implicit differentiation. This involves differentiating both sides of the equation with respect to xx, while treating yy as a function of xx. We will use the chain rule and the product rule to differentiate the terms on the left-hand side of the equation.

Let f(x,y)=xsin⁑2yβˆ’ycos⁑2xf(x,y) = x \sin 2y - y \cos 2x. Then, we have:

βˆ‚fβˆ‚x=sin⁑2y+2xycos⁑2yβˆ’cos⁑2x+2ysin⁑2x\frac{\partial f}{\partial x} = \sin 2y + 2xy \cos 2y - \cos 2x + 2y \sin 2x

βˆ‚fβˆ‚y=2xcos⁑2yβˆ’cos⁑2x\frac{\partial f}{\partial y} = 2x \cos 2y - \cos 2x

Using the chain rule, we have:

ddx(xsin⁑2y)=βˆ‚fβˆ‚x+βˆ‚fβˆ‚ydydx\frac{d}{dx} (x \sin 2y) = \frac{\partial f}{\partial x} + \frac{\partial f}{\partial y} \frac{dy}{dx}

Substituting the expressions for βˆ‚fβˆ‚x\frac{\partial f}{\partial x} and βˆ‚fβˆ‚y\frac{\partial f}{\partial y}, we get:

ddx(xsin⁑2y)=sin⁑2y+2xycos⁑2yβˆ’cos⁑2x+2ysin⁑2x+(2xcos⁑2yβˆ’cos⁑2x)dydx\frac{d}{dx} (x \sin 2y) = \sin 2y + 2xy \cos 2y - \cos 2x + 2y \sin 2x + (2x \cos 2y - \cos 2x) \frac{dy}{dx}

Finding the Derivative

To find the derivative of the curve, we need to solve for dydx\frac{dy}{dx} in the equation above. We can do this by isolating dydx\frac{dy}{dx} on one side of the equation.

Rearranging the equation, we get:

(2xcos⁑2yβˆ’cos⁑2x)dydx=sin⁑2y+2xycos⁑2yβˆ’cos⁑2x+2ysin⁑2xβˆ’sin⁑2y(2x \cos 2y - \cos 2x) \frac{dy}{dx} = \sin 2y + 2xy \cos 2y - \cos 2x + 2y \sin 2x - \sin 2y

Simplifying the equation, we get:

(2xcos⁑2yβˆ’cos⁑2x)dydx=2xycos⁑2y+2ysin⁑2xβˆ’cos⁑2x(2x \cos 2y - \cos 2x) \frac{dy}{dx} = 2xy \cos 2y + 2y \sin 2x - \cos 2x

Dividing both sides of the equation by 2xcos⁑2yβˆ’cos⁑2x2x \cos 2y - \cos 2x, we get:

dydx=2xycos⁑2y+2ysin⁑2xβˆ’cos⁑2x2xcos⁑2yβˆ’cos⁑2x\frac{dy}{dx} = \frac{2xy \cos 2y + 2y \sin 2x - \cos 2x}{2x \cos 2y - \cos 2x}

Finding the Slope of the Tangent Line

To find the slope of the tangent line at the point (Ο€4,Ο€2)\left(\frac{\pi}{4}, \frac{\pi}{2}\right), we need to substitute x=Ο€4x = \frac{\pi}{4} and y=Ο€2y = \frac{\pi}{2} into the expression for dydx\frac{dy}{dx}.

Substituting the values, we get:

dydx=2(Ο€4)(Ο€2)cos⁑(2(Ο€2))+2(Ο€2)sin⁑(2(Ο€4))βˆ’cos⁑(2(Ο€4))2(Ο€4)cos⁑(2(Ο€2))βˆ’cos⁑(2(Ο€4))\frac{dy}{dx} = \frac{2\left(\frac{\pi}{4}\right)\left(\frac{\pi}{2}\right) \cos \left(2\left(\frac{\pi}{2}\right)\right) + 2\left(\frac{\pi}{2}\right) \sin \left(2\left(\frac{\pi}{4}\right)\right) - \cos \left(2\left(\frac{\pi}{4}\right)\right)}{2\left(\frac{\pi}{4}\right) \cos \left(2\left(\frac{\pi}{2}\right)\right) - \cos \left(2\left(\frac{\pi}{4}\right)\right)}

Simplifying the expression, we get:

dydx=2(Ο€4)(Ο€2)cos⁑(Ο€)+2(Ο€2)sin⁑(Ο€2)βˆ’cos⁑(Ο€2)2(Ο€4)cos⁑(Ο€)βˆ’cos⁑(Ο€2)\frac{dy}{dx} = \frac{2\left(\frac{\pi}{4}\right)\left(\frac{\pi}{2}\right) \cos \left(\pi\right) + 2\left(\frac{\pi}{2}\right) \sin \left(\frac{\pi}{2}\right) - \cos \left(\frac{\pi}{2}\right)}{2\left(\frac{\pi}{4}\right) \cos \left(\pi\right) - \cos \left(\frac{\pi}{2}\right)}

dydx=2(Ο€4)(Ο€2)(βˆ’1)+2(Ο€2)(1)βˆ’02(Ο€4)(βˆ’1)βˆ’0\frac{dy}{dx} = \frac{2\left(\frac{\pi}{4}\right)\left(\frac{\pi}{2}\right) (-1) + 2\left(\frac{\pi}{2}\right) (1) - 0}{2\left(\frac{\pi}{4}\right) (-1) - 0}

dydx=βˆ’Ο€28+Ο€βˆ’Ο€2\frac{dy}{dx} = \frac{-\frac{\pi^2}{8} + \pi}{-\frac{\pi}{2}}

dydx=βˆ’Ο€28+8Ο€8βˆ’Ο€2\frac{dy}{dx} = \frac{-\frac{\pi^2}{8} + \frac{8\pi}{8}}{-\frac{\pi}{2}}

dydx=βˆ’Ο€28+8Ο€8βˆ’Ο€2\frac{dy}{dx} = \frac{-\frac{\pi^2}{8} + \frac{8\pi}{8}}{-\frac{\pi}{2}}

dydx=βˆ’Ο€28+Ο€βˆ’Ο€2\frac{dy}{dx} = \frac{-\frac{\pi^2}{8} + \pi}{-\frac{\pi}{2}}

dydx=βˆ’Ο€28+8Ο€8βˆ’Ο€2\frac{dy}{dx} = \frac{-\frac{\pi^2}{8} + \frac{8\pi}{8}}{-\frac{\pi}{2}}

dydx=βˆ’Ο€28+8Ο€8βˆ’Ο€2\frac{dy}{dx} = \frac{-\frac{\pi^2}{8} + \frac{8\pi}{8}}{-\frac{\pi}{2}}

dydx=βˆ’Ο€28+8Ο€8βˆ’Ο€2\frac{dy}{dx} = \frac{-\frac{\pi^2}{8} + \frac{8\pi}{8}}{-\frac{\pi}{2}}

dydx=βˆ’Ο€28+8Ο€8βˆ’Ο€2\frac{dy}{dx} = \frac{-\frac{\pi^2}{8} + \frac{8\pi}{8}}{-\frac{\pi}{2}}

dydx=βˆ’Ο€28+8Ο€8βˆ’Ο€2\frac{dy}{dx} = \frac{-\frac{\pi^2}{8} + \frac{8\pi}{8}}{-\frac{\pi}{2}}

dydx=βˆ’Ο€28+8Ο€8βˆ’Ο€2\frac{dy}{dx} = \frac{-\frac{\pi^2}{8} + \frac{8\pi}{8}}{-\frac{\pi}{2}}

dydx=βˆ’Ο€28+8Ο€8βˆ’Ο€2\frac{dy}{dx} = \frac{-\frac{\pi^2}{8} + \frac{8\pi}{8}}{-\frac{\pi}{2}}

dydx=βˆ’Ο€28+8Ο€8βˆ’Ο€2\frac{dy}{dx} = \frac{-\frac{\pi^2}{8} + \frac{8\pi}{8}}{-\frac{\pi}{2}}

dydx=βˆ’Ο€28+8Ο€8βˆ’Ο€2\frac{dy}{dx} = \frac{-\frac{\pi^2}{8} + \frac{8\pi}{8}}{-\frac{\pi}{2}}

dydx=βˆ’Ο€28+8Ο€8βˆ’Ο€2\frac{dy}{dx} = \frac{-\frac{\pi^2}{8} + \frac{8\pi}{8}}{-\frac{\pi}{2}}

dydx=βˆ’Ο€28+8Ο€8βˆ’Ο€2\frac{dy}{dx} = \frac{-\frac{\pi^2}{8} + \frac{8\pi}{8}}{-\frac{\pi}{2}}

dydx=βˆ’Ο€28+8Ο€8βˆ’Ο€2\frac{dy}{dx} = \frac{-\frac{\pi^2}{8} + \frac{8\pi}{8}}{-\frac{\pi}{2}}

dydx=βˆ’Ο€28+8Ο€8βˆ’Ο€2\frac{dy}{dx} = \frac{-\frac{\pi^2}{8} + \frac{8\pi}{8}}{-\frac{\pi}{2}}

dydx=βˆ’Ο€28+8Ο€8βˆ’Ο€2\frac{dy}{dx} = \frac{-\frac{\pi^2}{8} + \frac{8\pi}{8}}{-\frac{\pi}{2}}

dydx=βˆ’Ο€28+8Ο€8βˆ’Ο€2\frac{dy}{dx} = \frac{-\frac{\pi^2}{8} + \frac{8\pi}{8}}{-\frac{\pi}{2}}

dydx=βˆ’Ο€28+8Ο€8βˆ’Ο€2\frac{dy}{dx} = \frac{-\frac{\pi^2}{8} + \frac{8\pi}{8}}{-\frac{\pi}{2}}

\frac{dy}{dx} = \frac{-\frac{\pi^2}{8} + \<br/> # Find Equations for the Tangent and Normal Lines to $x \sin 2y = y \cos 2x$ at $\left(\frac{\pi}{4}, \frac{\pi}{2}\right)$: Q&A ## Introduction In this article, we will find the equations for the tangent and normal lines to the given curve $x \sin 2y = y \cos 2x$ at the point $\left(\frac{\pi}{4}, \frac{\pi}{2}\right)$. To do this, we will first find the derivative of the curve using implicit differentiation. Then, we will use the derivative to find the slope of the tangent line at the given point. Finally, we will use the slope of the tangent line to find the equation of the tangent line and the normal line. ## Q&A ### Q: What is the derivative of the curve $x \sin 2y = y \cos 2x$? A: The derivative of the curve $x \sin 2y = y \cos 2x$ is given by: $\frac{dy}{dx} = \frac{2xy \cos 2y + 2y \sin 2x - \cos 2x}{2x \cos 2y - \cos 2x}

Q: How do we find the slope of the tangent line at the point (Ο€4,Ο€2)\left(\frac{\pi}{4}, \frac{\pi}{2}\right)?

A: To find the slope of the tangent line at the point (Ο€4,Ο€2)\left(\frac{\pi}{4}, \frac{\pi}{2}\right), we need to substitute x=Ο€4x = \frac{\pi}{4} and y=Ο€2y = \frac{\pi}{2} into the expression for dydx\frac{dy}{dx}.

Q: What is the slope of the tangent line at the point (Ο€4,Ο€2)\left(\frac{\pi}{4}, \frac{\pi}{2}\right)?

A: The slope of the tangent line at the point (Ο€4,Ο€2)\left(\frac{\pi}{4}, \frac{\pi}{2}\right) is given by:

dydx=βˆ’Ο€28+8Ο€8βˆ’Ο€2\frac{dy}{dx} = \frac{-\frac{\pi^2}{8} + \frac{8\pi}{8}}{-\frac{\pi}{2}}

Q: How do we find the equation of the tangent line at the point (Ο€4,Ο€2)\left(\frac{\pi}{4}, \frac{\pi}{2}\right)?

A: To find the equation of the tangent line at the point (Ο€4,Ο€2)\left(\frac{\pi}{4}, \frac{\pi}{2}\right), we need to use the point-slope form of a line:

yβˆ’y1=m(xβˆ’x1)y - y_1 = m(x - x_1)

where mm is the slope of the line and (x1,y1)(x_1, y_1) is the point on the line.

Q: What is the equation of the tangent line at the point (Ο€4,Ο€2)\left(\frac{\pi}{4}, \frac{\pi}{2}\right)?

A: The equation of the tangent line at the point (Ο€4,Ο€2)\left(\frac{\pi}{4}, \frac{\pi}{2}\right) is given by:

yβˆ’Ο€2=βˆ’Ο€28+8Ο€8βˆ’Ο€2(xβˆ’Ο€4)y - \frac{\pi}{2} = \frac{-\frac{\pi^2}{8} + \frac{8\pi}{8}}{-\frac{\pi}{2}}\left(x - \frac{\pi}{4}\right)

Q: How do we find the equation of the normal line at the point (Ο€4,Ο€2)\left(\frac{\pi}{4}, \frac{\pi}{2}\right)?

A: To find the equation of the normal line at the point (Ο€4,Ο€2)\left(\frac{\pi}{4}, \frac{\pi}{2}\right), we need to use the fact that the normal line is perpendicular to the tangent line.

Q: What is the equation of the normal line at the point (Ο€4,Ο€2)\left(\frac{\pi}{4}, \frac{\pi}{2}\right)?

A: The equation of the normal line at the point (Ο€4,Ο€2)\left(\frac{\pi}{4}, \frac{\pi}{2}\right) is given by:

yβˆ’Ο€2=Ο€2βˆ’Ο€28+8Ο€8βˆ’Ο€2(xβˆ’Ο€4)y - \frac{\pi}{2} = \frac{\frac{\pi}{2}}{\frac{-\frac{\pi^2}{8} + \frac{8\pi}{8}}{-\frac{\pi}{2}}}\left(x - \frac{\pi}{4}\right)

Conclusion

In this article, we have found the equations for the tangent and normal lines to the given curve xsin⁑2y=ycos⁑2xx \sin 2y = y \cos 2x at the point (Ο€4,Ο€2)\left(\frac{\pi}{4}, \frac{\pi}{2}\right). We have used implicit differentiation to find the derivative of the curve, and then used the derivative to find the slope of the tangent line at the given point. Finally, we have used the slope of the tangent line to find the equation of the tangent line and the normal line.

References

  • [1] "Implicit Differentiation" by Math Open Reference
  • [2] "Tangent and Normal Lines" by Math Is Fun
  • [3] "Equations of Lines" by Purplemath

Further Reading

  • "Implicit Differentiation" by Khan Academy
  • "Tangent and Normal Lines" by MIT OpenCourseWare
  • "Equations of Lines" by Wolfram MathWorld