Let f(x)=2x2−7x+5 and g(x)=x2+9.
Find f⋅g, and f/g
i don't understand how to do this.
3 answers
Let f(x)=2x^2−7x+5 a IS A SQUARE
f "of" g = 2(x^2+9)^2-7(x^2+9) + 5
= 2x^2 + 18 - 7x^2 - 63 + 5
= - 5x^2 - 40
f / g = 2x^2-7x+5 / x^2 + 9
Factorise top and bottom
= (2x-5) (x-1) / (x+3)(x-3)
= 2x^2 + 18 - 7x^2 - 63 + 5
= - 5x^2 - 40
f / g = 2x^2-7x+5 / x^2 + 9
Factorise top and bottom
= (2x-5) (x-1) / (x+3)(x-3)
THis os a compositional function where:
f⋅g = f( (g)x) )
to solve it I substitute (x^2 + 9) for all values of x in the equation g(x) = 2x^2-7x+5
f⋅g = f( (g)x) )
to solve it I substitute (x^2 + 9) for all values of x in the equation g(x) = 2x^2-7x+5
5 answers