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Q1) In the polar coordinate plane, coordinate O is ( 0, 0° ) coordinate P is (3, 60°) coordinate Q is (3, 150°)Angle POQ is 90°How to find the length of PO and QO?How to find the area of triangle OPQ?Q2) A(3,0) and B(1,4) are two points in a retangular coordinate... 顯示更多 Q1) In the polar coordinate plane, coordinate O is ( 0, 0° ) coordinate P is (3, 60°) coordinate Q is (3, 150°) Angle POQ is 90° How to find the length of PO and QO? How to find the area of triangle OPQ? Q2) A(3,0) and B(1,4) are two points in a retangular coordinate plane. Suppose A' is the image obtained by reflecting A along the straight line y=k, where k is a constant and k>0. (a) Write down the coordinates of A' in terms of k. (b) If AB and A'B are perpendicular to each other, find the value of k.
最佳解答:
Q1How to find the length of PO and QO? PO = 3 QO = 3 angle POQ = 150? - 60? = 90? Area of triangle OPQ = (1/2)(PO)(QO) = (1/2)(3)(3) = 4.5 square unit. Q2. A' is (3,2k) slope of AB = (4-0)/(1-3) = -(4/2) = -2 slope of A'B = (2k-4)/(3-1) = 2(k-2)/2 = k-2 since AB perpendicular to A'B (-2)(k-2) = -1 -2k+4 = -1 5 = 2k k = 5/2
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