Can someone show me how to do this?
let f(x)=x^2+3x-1 and g(x)=x^3+4x^2+1
5 answers
do what?
Its a unit in algebra of functions and i dont know how to solve it
But you did not say what you want to do with the two functions
add them?
multiply them ?
add them?
multiply them ?
another idea might be composition.
(f◦g)(x) = f(g) = g^2+3g-1
= (x^3+4x^2+1)^2+3(x^3+4x^2+1)-1
= x^6+8x^5+16x^4+5x^3+20x^2+3
(g◦f)(x) = g(f) = f^3+4f^2+1
= (x^2+3x-1)^3+4(x^2+3x-1)^2+1
= x^6+9x^5+28x^4+33x^3+4x^2-15x+4
(f◦g)(x) = f(g) = g^2+3g-1
= (x^3+4x^2+1)^2+3(x^3+4x^2+1)-1
= x^6+8x^5+16x^4+5x^3+20x^2+3
(g◦f)(x) = g(f) = f^3+4f^2+1
= (x^2+3x-1)^3+4(x^2+3x-1)^2+1
= x^6+9x^5+28x^4+33x^3+4x^2-15x+4
I was afraid it might be that :)
1 answer