Hi, I do not understand how to do these questions, so if you can please show me how to do them with the corresponding work, and answer all of them, would be really great thank you. I attached 21-26 for your reference here for question 3.

21. x = rcost, y =r, ? =Isint, 120 22. X = COS I, V= Sin 17 = 1/(1 +/-) 23. x=n, y = 1/(1 +13), 2=1 24. x = cost, y = sint, ? = cos 21 25. X = Cos 81. V= sin 81, 7 120 26. X= COS I, V sin 1, ? = 1Many of the following are modified versions of exercises from Stewart's Multivariable Calculus. Note: while the concept of curvature below will not show up on the exams, it does appear in the labs. The curvature of a space curve with vector function r is given by K(t) = |r'(t) x r" (t) | |r (t) 13 1. Find parametric equations for two circles C1 and C2 in space such that . C1 and C2 have the same radius; . C1 and C2 intersect at the points P(1, 2, -1) and Q(1, 2, 1) and nowhere else. 2. Show that the space curve with parametric equation r(t) = (t - 2t2, 4 - 6t, t2 - 1) lies in a plane, and find an equation of this plane. Hint: try a plane ax + by + cz + d = 0. 3. Do exercises 21-26 of $13.1 of Stewart's Multivariable Calculus. 4. Find a parametric equation which describes the curve defined by intersecting the cylinder x2 + 2? = 625 with the revolutionary paraboloid 4y + (x2 + z2) = 0. Sketch the surfaces and the curve