2 a ∙ b = a² + b²
Subtract 2 a ∙ b to both sides
2 a ∙ b - 2 a ∙ b = a² + b² - 2 a ∙ b
0 = a² + b² - 2 a ∙ b
a² + b² - 2 a ∙ b = 0
a² - 2 a ∙ b + b² = 0
( a - b )² = 0
Take the square of both sides
a - b = 0
Add b to both sides
a - b + b = 0 + b
a = b
The statement is true if a = b
The assessment for this lesson is a discussion of a mathematical statement. You will have to determine if the statement is true or false. If it is false, you will explain your reasoning. For all real numbers a and b, 2a • b = a2 + b2
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