Question

Solve. Express your answer as exact roots.

(s+6)^2 = 3/4
Sq root (s+6)^2 = +-sq root 3/4
(s+6) = sq root 3/ 2

s = -6 +- sq root 3
-----------------
2

(The answer according to the textbook is (-12 +- sq root 3)/2. What error have I made?)

Thank you

Answer 1

(s+6)^2 = 3/4
s+6 = ±√3/2
s = -6±√3/2
This is where it helps to keep track of things

s = -6 ± (√3/2)
NOT
s = (-6±√3)/2

so, putting it all over 2,

s = (-12±√3)/2

Answer 2

Thank you!