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D Question 15 5 pts Let Ja) = 7, b = 5, and a . b = -21. If 0 is the angle between vectors a and b, find the following. 1. cos(0) = 2. Find the area of the parallelogram determined by the vectors a and b. area = (enter integers or fractions; must simplify your answers)288 D Question 13 5 pts Let C be a smooth curve represented by r(t) with T' (t) / 0, and let T, N, and B be the unit ? tangent vector, principal unit normal vector, and unit binormal vector of the curve C respectively. Calculate 1. N x B = 2. T . (T - 6N X B) = (enter numbers or expressions of T, N, B; for example, enter upper case I of T and enter IT for -T - - do not insert a space or parentheses)D Question 14 5 pts Consider the line L : x = 1 - 2t, y = t, z =5 - t and two planes P1 : 4x - 2y + 2z + 1 =0 P2 : 3x + 4y - 2z + 2 =0 Determine each plane is parallel to L, perpendicular to L, or neither. 1. P1 and L [ Select ] 2. P2 and L [ Select ]