Consider the curve given in polar coordinates bywith the origin as the pole and the positive –axis as the initial line.
- [(1)] Compute the area of the region enclosed by the curve .
- [(2)] At the point find the slope of the tangent line to the curve in the –coordinate plane. Let be the value obtained in part (1). Express the answer from part (2) in the formwhere and are integers, and let those integers be the definitions of and . Using these values of , , and , compute\
[THOUGHT] Let me solve this problem step by step.
Part (1): Area enclosed by the curve For a polar curve r = f(θ), the area is given by:
Part (2): Slope of tangent line For a polar curve, the slope in Cartesian coordinates is:
Given r = 2 + cos(θ), we have dr/dθ = -sin(θ)
At θ = π/4, I need to compute this slope.
Let me calculate both parts using Python. [/THOUGHT] [PYTHON] import sympy as sp from sympy import pi, cos, sin, sqrt, simplify, integrate, Rational
theta = sp.Symbol('theta')
Part (1): Area calculation
r = 2 + cos(theta) r_squared = r**2
Expand r^2
r_squared_expanded = sp.expand(r_squared) print("r^2 =", r_squared_expanded)
Area = (1/2) * integral from 0 to 2*pi of r^2 dtheta
area_integral = integrate(r_squared, (theta, 0, 2*pi)) area = Rational(1, 2) * area_integral print("Area =", area) print("Area simplified =", simplify(area))
Part (2): Slope of tangent line at theta = pi/4
dy/dx = (dr/dtheta * sin(theta) + r * cos(theta)) / (dr/dtheta * cos(theta) - r * sin(theta))
dr_dtheta = sp.diff(r, theta) print("\ndr/dtheta =", dr_dtheta)
At theta = pi/4
theta_val = pi/4
r_val = r.subs(theta, theta_val) dr_dtheta_val = dr_dtheta.subs(theta, theta_val)
print("r at pi/4 =", r_val) print("dr/dtheta at pi/4 =", dr_dtheta_val)
Numerator: dr/dtheta * sin(theta) + r * cos(theta)
numerator = dr_dtheta_val * sin(theta_val) + r_val * cos(theta_val)
Denominator: dr/dtheta * cos(theta) - r * sin(theta)
denominator = dr_dtheta_val * cos(theta_val) - r_val * sin(theta_val)
print("\nNumerator =", numerator) print("Denominator =", denominator)
slope = numerator / denominator slope_simplified = simplify(slope) print("\nSlope =", slope_simplified)
Let's rationalize and simplify further
slope_rationalized = sp.nsimplify(slope_simplified, rational=False) print("Slope rationalized =", slope_rationalized)
Let's expand this more carefully
slope_expanded = sp.simplify(sp.expand(slope_simplified)) print("Slope expanded =", slope_expanded) [/PYTHON]
[THOUGHT] From the Python calculations:
Part (1): The area enclosed by the curve is
Part (2): The slope of the tangent line is , which can be written as where and .
Now I need to compute:
Wait, let me recalculate:
The answer is . [/THOUGHT]
\boxed{-18}