Video: AQA GCSE Mathematics Foundation Tier Pack 4 β€’ Paper 2 β€’ Question 2

The value of 𝑍 is the square of the value of π‘Œ. Circle the correct formula. [A] π‘Œ = 𝑍² [B] 𝑍 = 2π‘Œ [C] 𝑍 = π‘ŒΒ² [D] 𝑍 = βˆšπ‘Œ.

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Video Transcript

The value of 𝑍 is the square of the value of π‘Œ. Circle the correct formula. Is it π‘Œ equals 𝑍 squared, 𝑍 equals two π‘Œ, 𝑍 equals π‘Œ squared, or 𝑍 equals the square root of π‘Œ.

As the question states, the value of 𝑍 is our formula must start 𝑍 equals. The word β€œis” in mathematics means equals. We’re told that 𝑍 is the square of π‘Œ. Squaring something means multiplying it by itself. Therefore, 𝑍 is equal to π‘Œ multiplied by π‘Œ. This can be written as 𝑍 is equal to π‘Œ squared. Any term multiplied by itself is the same as that term squared. If 𝑍 is the square of the value of π‘Œ, the correct formula is 𝑍 equals π‘Œ squared.

The first incorrect answer has the variables the wrong way round. π‘Œ is equal to 𝑍 squared. This means that π‘Œ is the square of the value of 𝑍. The second incorrect answer states that 𝑍 is equal to two π‘Œ. This means 𝑍 is equal to two multiplied by π‘Œ. This would also be the simplified version of 𝑍 equals π‘Œ plus π‘Œ as π‘Œ plus π‘Œ is equal to two π‘Œ. The third incorrect answer states that 𝑍 is equal to the square root of π‘Œ.

The first and last formula are actually both the same. If we squared both sides of the last formula, we would get 𝑍 squared is equal to the square root of π‘Œ squared. As squaring and square rooting are inverse or the opposite of each other, the right-hand side just becomes π‘Œ. This leaves us with π‘Œ is equal to 𝑍 squared, which is the same as the first formula.

None of these three answers are the correct formula if 𝑍 is the square of the value of π‘Œ.

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