xi). This function — specifically, its zeros — are at the basis of Riemann's hypothesis, an unsolved problem in pure mathematics Riemann Zeta function, depicted, the modulus of ζ(1/2 +i). This function — specifically, its zeros — are at the basis of Riemann's hypothesis, an unsolved problem in pure mathematics

Broadly speaking, pure mathematics is mathematics motivated entirely for reasons other than application. From the eighteenth century onwards, this was a recognised category of mathematical activity, sometimes characterised as speculative mathematics, and at variance with the trend towards meeting the needs of navigation, astronomy, physics, engineering and so on.

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