Question

If f(x) =3x2 and g(x)=4x3+1, what the degree of (f•g)(x)? 2 3 5 6

Answer 1

f(x) = 3x²

g(x) = 4x³ + 1

f(g(x)) = 3.(4x³ + 1)²

As we know

(a + b)² = a² + 2.a.b + b²

So,

(4x³ + 1) = (4x³)² + 2.4x³.1 + 1² = $4x^6+8x^3+1$

f(g(x)) = 3.($4x^6+8x^3+1$)

The degree is the maximum exponent, so, 6.