Identifying surfaces

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We identify surfaces.

Work in groups of 3–4, writing your answers on a separate sheet of paper.

Match the following functions to the level curves.

(a): $3xy-x^3-y^3+\frac {1}{16}$
(b): $\frac {3x}{2} -\frac {x^3}{2} - xy^2+\frac {1}{16}$
(c): $x^4-2x^2+y^2-\frac {17}{16}$
(d): $-2x^3-3y^4+6xy^2+\frac {1}{16}$
(e): $x^4-y^4-2x^2+2y^2+\frac {1}{16}$
(f): $-x^4+4xy-2y^2+ \frac {1}{16}$

(i)
(ii)
(iii)
(iv)
(v)
(vi)