Question

Let f(y) = y^4 - 3y^3 + y - 3 and g(y) = y^3 + 7y^2 - 2. Find f(y) + g(y). Write your answer as a polynomial with terms of decreasing degree.

Answer 1

Answer: y^4 - 2y^3 + 7y^2 + y - 5

Work Shown:

h(y) = f(y) + g(y)

h(y) = (y^4 - 3y^3 + y - 3) + (y^3 + 7y^2 - 2)

h(y) = y^4 - 3y^3 + y - 3 + y^3 + 7y^2 - 2

h(y) = y^4 + (-3y^3+y^3) + 7y^2 + y + (-3 - 2)

h(y) = y^4 - 2y^3 + 7y^2 + y - 5

This is a fourth degree polynomial (aka quartic).