20.* 1 point what is vertex of the cone ax + by +cz + 2fyz + 2gzx + 2hxy = 0 (a) .g.h) (c)(1,1,1) (b) (a, b, c) (d) (0,0,0) o a o b o c od * 21. 1 point equatio

20.* 1 point What is vertex of the cone ax + by +cz + 2fyz + 2gzx + 2hxy = 0 (a) .g.h) (C)(1,1,1) (b) (a, b, c) (d) (0,0,0) O a O b O C Od * 21. 1 point Equation of the cone whose vertex is origin and base curve is z k,f(X,y)=0 (a) f(xz/k,yz/k) (c) f(k/x, k/y) (b) f(kx/z, ky/2) (d) None of these