Question

Which SQL expression calculates the square root of 16?

• A. POWER(16,2)
• B. POWER(16,0.5)
• C. POWER(16,1)
• D. MOD(16)

Answer 1

The Correct Option is B

To determine which SQL expression calculates the square root of 16, we need to evaluate the options provided: 

• POWER(16,2): This expression calculates 16 squared, which is 256.
• POWER(16,0.5): This expression calculates the square root of 16. Raising a number to the power of 0.5 is equivalent to taking its square root. Thus, 160.5 = 4.
• POWER(16,1): This expression returns 16 because any number raised to the power of 1 is the number itself.
• MOD(16): This expression represents the modulus operation, which is unrelated to square roots and requires a second operand to function correctly.

From this evaluation, the correct SQL expression to calculate the square root of 16 is POWER(16,0.5).

Answer 2

The SQL expression that calculates the square root of 16 is POWER(16, 0.5).

Additional Context:

• Mathematical Principle:
  • Square root is equivalent to raising to the power of 0.5
  • √x = x^(1/2)
• SQL Function Analysis:
  • POWER(16,0.5) (2): Correct calculation → 4
  • POWER(16,2) (1): Calculates 16² → 256
  • POWER(16,1) (3): Returns 16¹ → 16
  • MOD(16) (4): Missing parameters (modulo operation)
• Alternative Functions:
  • SQRT(16) - Direct square root function
  • POW(16,0.5) - Synonym in some databases
• Database Compatibility:
  • Works in MySQL, PostgreSQL, SQL Server, Oracle
  • Syntax consistent across platforms

Correct Answer: (2) POWER(16,0.5).