9514 1404 393
Answer:
Explanation:
The Pythagorean theorem relates the sides of a right triangle.
x² + y² = 5²
x² = 25 -y²
x = √(25 -y²)
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The cosine function relates the adjacent side and the hypotenuse of an acute angle in a right triangle.
Cos = Adjacent/Hypotenuse
Adjacent = Hypotenuse × Cos
x = 5·cos(Ф)