If a(x) = 2x - 4 and b(x) = x + 2, which of the following expressions produces a quadratic function?
o (ab)(x)
o (a - b)(x)
o (a + b)(x)

Produces quadratic function  

Solution:

Given that    

a (x) = 2x – 4  and b(x)  = x + 2

Need to check which of the expression from given three expression produce a quadratic function. Let us solve each option and check the result.

So (ab)(x) produces a quadratic function

So (a - b)(x) produces a linear function x – 6.

So (a + b)(x) produces a linear function x – 2.

Hence we can conclude that (ab)(x) produces quadratic function.