All flashcards Flashcard 1: State the formula for arc length in polar coordinates. Answer: L = ∫ θ 1 θ 2 r 2 + ( r ′ ) 2 d θ L = \int_{\theta_1}^{\theta_2} \sqrt{r^2 + (r')^2} \, d\theta L = ∫ θ 1 θ 2 r 2 + ( r ′ ) 2 d θ . Integrates r 2 + ( d r d θ ) 2 \sqrt{r^2 + \left( \frac{dr}{d\theta} \right)^2} r 2 + ( d θ d r ) 2
Flashcard 2: State the formula for x x x in terms of r r r and θ \theta θ . Answer: x = r × cos ( θ ) x = r \times \cos(\theta) x = r × cos ( θ ) . Horizontal component uses cosine.
Flashcard 3: What is the general form of a polar coordinate? Answer: ( r , θ ) (r, \theta) ( r , θ ) . Distance from origin and angle from positive x-axis.
Flashcard 4: What is the formula for the slope of a tangent line in polar coordinates? Answer: d y d x = r ′ sin ( θ ) + r cos ( θ ) r ′ cos ( θ ) − r sin ( θ ) \frac{dy}{dx} = \frac{r' \sin(\theta) + r \cos(\theta)}{r' \cos(\theta) - r \sin(\theta)} d x d y = r ′ c o s ( θ ) − r s i n ( θ ) r ′ s i n ( θ ) + r c o s ( θ ) . Derivative of y with respect to x in polar form.
Flashcard 5: What is the polar form of a spiral of Archimedes? Answer: r = a + b θ r = a + b\theta r = a + b θ . Spiral increasing linearly with angle.
Flashcard 6: What is the formula for r r r in terms of x x x and y y y ? Answer: r = sqrt ( x 2 + y 2 ) r = \text{sqrt}(x^2 + y^2) r = sqrt ( x 2 + y 2 ) . Pythagorean theorem applied to coordinates.
Flashcard 7: Find the maximum value of r = 2 + 3 cos ( θ ) r = 2 + 3\text{cos}(\theta) r = 2 + 3 cos ( θ ) . Answer: Maximum r = 5 r = 5 r = 5 . Maximum occurs when cos ( θ ) = 1 \cos(\theta) = 1 cos ( θ ) = 1 .
Flashcard 8: Convert the Cartesian coordinate ( x , y ) (x, y) ( x , y ) to polar coordinates. Answer: ( r , θ ) = ( sqrt ( x 2 + y 2 ) , tan − 1 ( y x ) ) (r, \theta) = (\text{sqrt}(x^2 + y^2), \text{tan}^{-1}(\frac{y}{x})) ( r , θ ) = ( sqrt ( x 2 + y 2 ) , tan − 1 ( x y )) . Distance formula and arctangent for angle.
Flashcard 9: What is the formula for θ \theta θ in terms of x x x and y y y ? Answer: θ = tan − 1 ( y x ) \theta = \text{tan}^{-1}(\frac{y}{x}) θ = tan − 1 ( x y ) . Inverse tangent of y over x ratio.
Flashcard 10: What is the polar form of a limaçon with an inner loop? Answer: r = a + b cos ( θ ) r = a + b\text{cos}(\theta) r = a + b cos ( θ ) where a < b a < b a < b . When a < b a < b a < b , creates inner loop.
Flashcard 11: Convert the polar coordinate ( r , θ ) (r, \theta) ( r , θ ) to Cartesian coordinates. Answer: ( x , y ) = ( r × cos ( θ ) , r × sin ( θ ) ) (x, y) = (r \times \text{cos}(\theta), r \times \text{sin}(\theta)) ( x , y ) = ( r × cos ( θ ) , r × sin ( θ )) . Use x = r cos ( θ ) x = r\cos(\theta) x = r cos ( θ ) and y = r sin ( θ ) y = r\sin(\theta) y = r sin ( θ ) .
Flashcard 12: What is the expression for d y / d x dy/dx d y / d x in polar coordinates? Answer: d y d x = r ′ sin ( θ ) + r cos ( θ ) r ′ cos ( θ ) − r sin ( θ ) \frac{dy}{dx} = \frac{r' \text{sin}(\theta) + r \text{cos}(\theta)}{r' \text{cos}(\theta) - r \text{sin}(\theta)} d x d y = r ′ cos ( θ ) − r sin ( θ ) r ′ sin ( θ ) + r cos ( θ ) . Chain rule applied to parametric equations.
Flashcard 13: Identify the polar form of a circle centered at the origin with radius a a a . Answer: r = a r = a r = a . Constant radius equals constant distance from origin.
Flashcard 14: Convert the Cartesian equation x 2 + y 2 = 4 x^2 + y^2 = 4 x 2 + y 2 = 4 to polar form. Answer: r = 2 r = 2 r = 2 . Circle centered at origin with radius 2 2 2 .
Flashcard 15: What is the polar area formula for a sector? Answer: Area = 1 2 × r 2 × θ \frac{1}{2} \times r^2 \times \theta 2 1 × r 2 × θ . Half the product of radius squared and central angle.
Flashcard 16: State the formula for y y y in terms of r r r and θ \theta θ . Answer: y = r × sin ( θ ) y = r \times \text{sin}(\theta) y = r × sin ( θ ) . Vertical component uses sine.
Flashcard 17: What is the formula for θ \theta θ in terms of x x x and y y y ? Answer: θ = tan − 1 ( y x ) \theta = \text{tan}^{-1}(\frac{y}{x}) θ = tan − 1 ( x y ) . Inverse tangent of y over x ratio.
Flashcard 18: State the formula for x x x in terms of r r r and θ \theta θ . Answer: x = r × cos ( θ ) x = r \times \text{cos}(\theta) x = r × cos ( θ ) . Horizontal component uses cosine.
Flashcard 19: What is the formula for the slope of a tangent line in polar coordinates? Answer: d y d x = r ′ sin ( θ ) + r cos ( θ ) r ′ cos ( θ ) − r sin ( θ ) \frac{dy}{dx} = \frac{r' \text{sin}(\theta) + r \text{cos}(\theta)}{r' \text{cos}(\theta) - r \text{sin}(\theta)} d x d y = r ′ cos ( θ ) − r sin ( θ ) r ′ sin ( θ ) + r cos ( θ ) . Derivative of y with respect to x in polar form.
Flashcard 20: What is the polar form of a spiral of Archimedes? Answer: r = a + b θ r = a + b\theta r = a + b θ . Spiral increasing linearly with angle.
Flashcard 21: Find the maximum value of r = 2 + 3 cos ( θ ) r = 2 + 3\text{cos}(\theta) r = 2 + 3 cos ( θ ) . Answer: Maximum r = 5 r = 5 r = 5 . Maximum occurs when cos ( θ ) = 1 \cos(\theta) = 1 cos ( θ ) = 1 .
Flashcard 22: Convert the Cartesian coordinate ( x , y ) (x, y) ( x , y ) to polar coordinates. Answer: ( r , θ ) = ( sqrt ( x 2 + y 2 ) , tan − 1 ( y x ) ) (r, \theta) = (\text{sqrt}(x^2 + y^2), \text{tan}^{-1}(\frac{y}{x})) ( r , θ ) = ( sqrt ( x 2 + y 2 ) , tan − 1 ( x y )) . Distance formula and arctangent for angle.
Flashcard 23: What is the polar form of a limaçon with an inner loop? Answer: r = a + b cos ( θ ) r = a + b\text{cos}(\theta) r = a + b cos ( θ ) where a < b a < b a < b . When a < b a < b a < b , creates inner loop.
Flashcard 24: Convert the polar coordinate ( r , θ ) (r, \theta) ( r , θ ) to Cartesian coordinates. Answer: ( x , y ) = ( r × cos ( θ ) , r × sin ( θ ) ) (x, y) = (r \times \text{cos}(\theta), r \times \text{sin}(\theta)) ( x , y ) = ( r × cos ( θ ) , r × sin ( θ )) . Use x = r cos ( θ ) x = r\cos(\theta) x = r cos ( θ ) and y = r sin ( θ ) y = r\sin(\theta) y = r sin ( θ ) .
Flashcard 25: What is the formula for r r r in terms of x x x and y y y ? Answer: r = sqrt ( x 2 + y 2 ) r = \text{sqrt}(x^2 + y^2) r = sqrt ( x 2 + y 2 ) . Pythagorean theorem applied to coordinates.
Flashcard 26: State the formula for y y y in terms of r r r and θ \theta θ . Answer: y = r × sin ( θ ) y = r \times \text{sin}(\theta) y = r × sin ( θ ) . Vertical component uses sine.
Flashcard 27: What is the polar area formula for a sector? Answer: Area = 1 2 × r 2 × θ \frac{1}{2} \times r^2 \times \theta 2 1 × r 2 × θ . Half the product of radius squared and central angle.
Flashcard 28: What is the general form of a polar coordinate? Answer: ( r , θ ) (r, \theta) ( r , θ ) . Distance from origin and angle from positive x-axis.
Flashcard 29: Convert the Cartesian equation x 2 + y 2 = 4 x^2 + y^2 = 4 x 2 + y 2 = 4 to polar form. Answer: r = 2 r = 2 r = 2 . Circle centered at origin with radius 2 2 2 .
Flashcard 30: Identify the polar form of a circle centered at the origin with radius a a a . Answer: r = a r = a r = a . Constant radius equals constant distance from origin.