Question

Considere as funçoes f(x)=3x2+x-1 e gx)=2x+5.Determine

a)f(g(x))

b)g(f(x))

Answer 1

a) 3(2x+5)²+2x+5-1 = 3(4x²+20x+25)+2x+4 = 12x²+60x+75+2x+4 = 12x²+62x+79

b) 2(3x²+x-1)+5 = 6x²+2x-2+5 = 6x²+2x+3

Answer 2

a)f(x)= 6+x-1 = 5+x /x=-5 b) 2x+5 /x=5/2