Find a cartesian equation for the curve and identify it: r²sin2θ = 1.  or  2. let vectors a = (2, 1, 3), b = (-5, 2, 1), and c = (2, 1, 1). find the volume of the parallelepiped defined by vectors a, b, and c by calculating a ● (b x c) using the dot and cross product rules.  answer to #2: i j k(-5) 2 12 1 1= 2 1 i1 1 i= 5 1 j2 1 j= (-5) 2 k2 1 k= (2×1-1×1)i- (5×1-2×1)j + ) ×1-2×2)k=1i=3j=(-9)k=(1,)) =b×c=(2,1,3)×(1,3,9)=(2×1)+(1×3)+(3 ×(-9))=2+3+(-27)=(-22)v=/-22\=22