What is the distance between (4 ,( 9 pi)/8 )(4,9π8) and (-4 ,( 3pi )/2 )(−4,3π2)? Trigonometry The Polar System Polar Coordinates 1 Answer Harish Chandra Rajpoot Jul 19, 2018 6.6517\ \text{unit} Explanation: The distance between the points (r_1, \theta_1)\equiv(4, {9\pi}/8) & (r_2, \theta_2)\equiv(-4, {3\pi}/2) is given by the formula as follows \sqrt{r_1^2+r_2^2-2r_1r_2\cos(\theta_1-\theta_2)} =\sqrt{4^2+(-4)^2-2(4)(-4)\cos({9\pi}/8-{3\pi}/2)} =\sqrt{32+32\cos({3\pi}/8)} =4\sqrt2\sqrt{1+\sin({\pi}/8)} =6.6517\ \text{unit} Answer link Related questions What are Polar Coordinates? How do you find the polar coordinates of the point? What is the difference between a rectangular coordinate system and a polar coordinate system? How do you graph polar coordinates? What careers use polar coordinates? How do you plot the point A (5, -255^\circ) and the point B (3, 60^\circ)? What does a polar coordinate system look like? How do you find the distance between 2 polar coordinates? For the given point A(-4, frac{pi}{4}), how do you list three different pairs of polar... How do you find the rectangular form of (4, -pi/2)? See all questions in Polar Coordinates Impact of this question 1601 views around the world You can reuse this answer Creative Commons License