Math. [f. BI- pref.2 + QUADRATE, ad. L. quadrātus squared.] The square of the square (power or root); the fourth power in arithmetic and algebra; = BIQUADRATIC.

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1706.  Phillips, Biquadrate,… the fourth Power in Arithmetic and Algebra.

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1806.  Hutton, Course Math., I. 171. Its … cube (a3), or biquadrate (a4). Ibid., I. 203. The biquadrate root of 16 a4–96a3x+216a2x2–216 ax3+81x4.

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