The square root of 5 is the positive real number that, when multiplied by itself, gives the prime number 5. It is more precisely called the principal square root of 5, to distinguish it from the negative number with the same property. This number appears in the fractional expression for the golden ratio. It can be denoted in surd form as:
It is an irrational algebraic number. The first sixty significant digits of its decimal expansion are:
- 2.23606 79774 99789 69640 91736 68731 27623 54406 18359 61152 57242 7089... (sequence A002163 in OEIS).
which can be rounded down to 2.236 to within 99.99% accuracy. As of April 1994, its numerical value in decimal had been computed to at least one million digits.
Read more about Square Root Of 5: Proof of Irrationality, Continued Fraction, Babylonian Method, Relation To The Golden Ratio and Fibonacci Numbers, Geometry, Trigonometry, Diophantine Approximations, Algebra, Identities of Ramanujan, See Also
Famous quotes containing the words square and/or root:
“Rationalists, wearing square hats,
Think, in square rooms,
Looking at the floor,
Looking at the ceiling.
They confine themselves
To right-angled triangles.”
—Wallace Stevens (1879–1955)
“Flower in the crannied wall,
I pluck you out of the crannies,
I hold you here, root and all, in my hand,
Little flower—but if I could understand
What you are, root and all, and all in all,
I should know what God and man is.”
—Alfred Tennyson (1809–1892)