Question

.

Answer 1

Answer:

$k = 4$

Step-by-step explanation:

Given

$4x^2 - 8x + k$

Required

Determine k if the expression is a perfect square

A quadratic is of the form;

$ax^2 + bx + c$

Where (by comparison):

$a = 4$     $b = 8$     $c = k$

If the above is a perfect square, then

$k = \frac{b^2}{4a}$

Substitute values for a, b and c

$k = \frac{8^2}{4*4}$

$k = \frac{64}{16}$

$k = 4$

Hence, k = 4