Question

(a) Use the fundamental theorem of algebra to determine the number of roots for 2x^2 + 4x + 7

Answer 1

Answer:

Step-by-step explanation:

A 2nd order polynomial such as this one will have 2 roots; a 3rd order polynomial 3 roots, and so on.

The quadratic formula is one of the faster ways (in this situation, at least) in which to find the roots.  From 2x^2 + 4x + 7 we get a = 2, b = 4 and c = 7.

Then the discriminant is b^2 - 4ac, or, here, 4^2 - 4(2)(7), or -40.  Because the discriminant is negative, we know that the roots will be complex and unequal.

Using the quadratic formula:

       -4 ±√[-40]         -4 ± 2i√10

x  = ------------------ = ------------------

                4                       4

                                       -2 ± i√10

Thus, the roots are x = ------------------

                                               2