Suppose f: B → C and g: A → Bare functions. Check all the statements that are true A. If fog is 1-1 and f is not, then g cannot be onto. ✔B. If fog is 1-1, then so is g. ✓C. If fog is 1-1 and g is not, then f cannot be onto. D. If f and g are both 1-1, then so is fog. E. If fog is 1-1, then so is f. F. None of the above

Show that if ax2+bx+c=0 for all x, then a=b=c=0.

In each of the following parts, a relation is defined on the set of all human beings. Determine whether the relation is reflective, symmetric, or transitive. Justify your answers. xRy if and only if x lives within 400 miles of y. xRy if and only if x is the father of y. xRy if and only if x is a first cousin of y. xRy if and only if x and y were born in the same year. xRy if and only if x and y have the same mother. xRy if and only if x and y have the same hair colour.