Given that x2 + y2 + z2 = 194, calculate z if x = 7 and \(\sqrt{y}\) = 3
A
\(\sqrt{10}\)
B
8
C
12.2
D
13.4
Verified Correct Answer: B.
Step-by-Step Mathematical Solution
Given that x2 + y2 + z2 = 194, calculate z if x = 7 and \(\sqrt{y}\) = 3
x = 7
∴ x2 = 49
\(\sqrt{y}\) = 3
∴ y2 = 81 = x2 + y2 + z2 = 194
49 + 81 + z2 = 194
130 + z2 = 194
z2 = 194 - 130
= 64
z = \(\sqrt{64}\)
= 8
Source: Myschool Past Questions Archive (Record #31470)