do question 2 (show that...) and question 3( let r and h..) please

5.2 Show that the following parametrizations are unit speed (a) P1 ( s) = = (s + VS2 + 1, (s + V s2 + 1) -1, V2log(s + vs2 + 1)). S E [0, 1] + 3 / 2 (c) P3 (s) = = cos (s) - SV 1 - s2, 1 - s2, 0), s E [0, 1]. 3 Let r and h denote positive numbers. Find a unit speed parametrization of the helix P (t) = (r cost, r sint, ht), 0