The short answer is trial and error. The side lengths "3" and "4" can both be substituted for a² and b² but not c² because their value squared is not high enough since 5² is 25. "c²" as to match the longest side because the smaller numbers will cause the equation to not be true. See Below.
a² + b² = c²
3² + 4² = 5²
9 + 16 = 25
25 = 25
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a² + b² = c²
4² + 3² = 5²
16 + 9 = 25
25 = 25
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a² + b² = c²
5² + 4² = 3²
25 + 16 = 9
41 ≠ 9
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a² + b² = c²
3² + 5² = 4²
9 + 25 = 16
34 ≠ 16
Hope this helped!
No. It is quadratic since it would cross the x-axis twice
f(g(-1)) = - 3
Evaluate g(-1) and substitute into f(x)
g(-1) = (-1)² -7(-1) - 9 = 1 + 7 - 9 = - 1
f(g(-1)) = (-1) - 2 = - 3
