If (sqrt{x^2 + 9}) = x + 1, solve for x
-
A.
5 -
B.
4 -
C.
3 -
D.
2 -
E.
1
Correct Answer: Option B
Explanation
(sqrt{x^2 + 9}) = x + 1
x2 + 9 = (x + 1)2 + 1
0 = x2 + 2x + 1 – x2 – 9
= 2x – 8 = 0
2(x – 4) = 0
x = 4
(sqrt{x^2 + 9}) = x + 1
x2 + 9 = (x + 1)2 + 1
0 = x2 + 2x + 1 – x2 – 9
= 2x – 8 = 0
2(x – 4) = 0
x = 4