Question

If x = 1, y = 2 and z = 3 then (x² + y² + z²) = ?

Options

• 6

• 12

• 14

• 15

Answer 1

14
Substituting x = 1, y = 2 and z = 3 in (x² + y² + z²):

\[\left( 1 \right)^2 + \left( 2 \right)^2 + \left( 3 \right)^2\]
or, 1 + 4 + 9 = 14