or maximum values and their zeros are real or complex show work. function f(x) 5 less than 3 times the square of a number increased by 4 times the number. function g(x): 5 more than the opposite of 3 times the square of a number increased by 4 times the number
Converting to formulae: f(x)=3x^2-5+4x. g(x)=5-3x^2+4x . Putting in descending powers,
f(x)=3x^2+4x-5 ; g(x)=-3x^2+4x+5 . Because the quadratic term dominates as |x| goes to infinity, it is clear that f is concave up whereas g is concave down. Thus f has a minimum whereas g has a maximum. f must have real zeroes because when x=0 f is negative, and f assumes positive values. Thus it must cross the x axis to get there. Similarly, g has real zeroes because when x=0 g is positive but g assumes negative values and must cross the x axis to get there.