Math Problem Statement

please give me an explicit solution about a and b for r and theta.

Please give me an explicit solution about a and b for r and theta.

Solution

We aim to solve the system of equations for aa and bb in terms of rr and θ\theta explicitly.

From the image, the equations are:

  1. (crcosθ)2(a(crcosθ)+b)=rsinθ(c - r \cos\theta)^2 \big(a(c - r \cos\theta) + b\big) = r \sin\theta

  2. (crcosθ)(3a(crcosθ)+2b)=cosθsinθ(c - r \cos\theta)\big(3a - (c - r \cos\theta) + 2b\big) = \frac{\cos\theta}{\sin\theta}

We will proceed to isolate aa and bb. Let me compute this step-by-step. sympy import symbols, Eq, solve, cos, sin

Define variables

a, b, c, r, theta = symbols('a b c r theta')

Define the two equations

eq1 = Eq((c - rcos(theta))2 * (a(c - rcos(theta)) + b), rsin(theta)) eq2 = Eq((c - rcos(theta)) * (3a - (c - rcos(theta)) + 2b), cos(theta)/sin(theta))

Solve the system of equations for a and b

solution = solve([eq1, eq2], (a, b)) solutionThe explicit solutions for aa and bb in terms of rr, θ\theta, and cc are:

Solution for aa:

a=c3sinθ3c2rcosθsinθ+3cr2cos2θsinθ+ccosθr3cos3θsinθ2rsin2θrcos2θ2c3sinθ+6c2rcosθsinθ+3c2sinθ6cr2cos2θsinθ6crcosθsinθ+2r3cos3θsinθ+3r2cos2θsinθa = \frac{c^3 \sin\theta - 3 c^2 r \cos\theta \sin\theta + 3 c r^2 \cos^2\theta \sin\theta + c \cos\theta - r^3 \cos^3\theta \sin\theta - 2 r \sin^2\theta - r \cos^2\theta}{-2 c^3 \sin\theta + 6 c^2 r \cos\theta \sin\theta + 3 c^2 \sin\theta - 6 c r^2 \cos^2\theta \sin\theta - 6 c r \cos\theta \sin\theta + 2 r^3 \cos^3\theta \sin\theta + 3 r^2 \cos^2\theta \sin\theta}

Solution for bb:

b=c4sinθ+4c3rcosθsinθ6c2r2cos2θsinθc2cosθ+4cr3cos3θsinθ+2crcos2θr4cos4θsinθr2cos3θ+3rsin2θ2c3sinθ+6c2rcosθsinθ+3c2sinθ6cr2cos2θsinθ6crcosθsinθ+2r3cos3θsinθ+3r2cos2θsinθb = \frac{-c^4 \sin\theta + 4 c^3 r \cos\theta \sin\theta - 6 c^2 r^2 \cos^2\theta \sin\theta - c^2 \cos\theta + 4 c r^3 \cos^3\theta \sin\theta + 2 c r \cos^2\theta - r^4 \cos^4\theta \sin\theta - r^2 \cos^3\theta + 3 r \sin^2\theta}{-2 c^3 \sin\theta + 6 c^2 r \cos\theta \sin\theta + 3 c^2 \sin\theta - 6 c r^2 \cos^2\theta \sin\theta - 6 c r \cos\theta \sin\theta + 2 r^3 \cos^3\theta \sin\theta + 3 r^2 \cos^2\theta \sin\theta}

Both aa and bb are expressed as fractions with the same denominator, which depends on rr, θ\theta, and cc.

Next Steps:

Let me know if you would like:

  1. A simplification of these expressions for specific cases.
  2. Numerical evaluations for specific values of rr, θ\theta, and cc.
  3. Visualizations or a step-by-step derivation of the solutions.
  4. Further insights into the dependency of aa and bb on θ\theta and rr.
  5. An exploration of the geometric meaning of these equations.

Tip: When solving trigonometric equations, always check for scenarios where sinθ\sin\theta or cosθ\cos\theta might lead to undefined results or special cases like θ=0\theta = 0 or π/2\pi/2.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Algebraic Equations
Trigonometric Functions
System of Equations

Formulas

(c - r * cos(θ))² * (a(c - r * cos(θ)) + b) = r * sin(θ)
(c - r * cos(θ))(3a - (c - r * cos(θ)) + 2b) = cos(θ) / sin(θ)

Theorems

Properties of Trigonometric Functions
Techniques for Solving Simultaneous Equations

Suitable Grade Level

Undergraduate Level