2 求 xy 平面上與正 x 軸夾角為 0.3π，長度為 3 的向量 F 為何？
(A)F = 3cos(0.3π)i+3sin(0.3π)j
(B)F = 3sin(0.3π)i+3cos(0.3π)j
(C)F = 3cos(0.3π)i－3sin(0.3π)j
(D)F = 3sin(0.3π)i－3cos(0.3π)j

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統計： A(4), B(0), C(1), D(0), E(0) #1373241