# how to get a isosceles trapezoid plot

I made a square plot using $(x^{16}+y^{16})^{1/32}$ like below,and now I want make a isosceles trapezoid or just move center's square more upper, just like standing in a cave,triangle at bottom should bigger than top's triangle ,sorry for my bad English .so how to plot it using math formula,how to solve this ? thank you !

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Perhaps you mean something like \eqalign{ \left( \left( 5\,y+2\,{x}^{2}+2\,{y}^{2}+2 \right) ^{32}\right. &+ \left( -5 \,y+2\,{x}^{2}+2\,{y}^{2}+2 \right) ^{32}\cr+ \left( -4\,x+y+2\,{x}^{2}+2 \,{y}^{2}+2 \right) ^{32}&+ \left.\left( 4\,x+y+2\,{x}^{2}+2\,{y}^{2}+2 \right) ^{32} \right) ^{1/32}\cr&-2\,{x}^{2}-2\,{y}^{2}-2 }

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you're right,thank you –  ifree Nov 6 '12 at 9:10

You could try $((x-y)^{16}+y^{16})^{1/32}$.

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hi @joriki,thanks for your answer ,sorry for my lack of description,how about isosceles trapezoid's formula –  ifree Nov 6 '12 at 3:55

How about $\left(x(\frac{3}{2}-\frac{1}{2}y)\right)^{16}+y^{16}$ ?

EDIT: If you want it with the wider part on the bottom, just use $\left(x(\frac{3}{2}+\frac{1}{2}y)\right)^{16}+y^{16}$.

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thank you @Mattew Conroy ,I need to clarify my question –  ifree Nov 6 '12 at 4:30
@ifree I have edited my answer to give you another option. –  Matthew Conroy Nov 6 '12 at 6:11