# Riken 実用理科技能検定理検|理科検定

「理検」理科検定(実用理科技能検定)は理科の学習者を積極的に顕彰・評価し、

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### T-expressionGraphic DesignMath Art  $T\sum [\sin(x^2+y^2)=t]$Trigonometric function “ sine or cosine ” expresses periodicity. Quadratic expression "$$\left(x^2+y^2\right)$$" shows circular shape.
Expression factor "$$t$$" associates these characteristics.
T-expression , Math Art skill is investigated by TAKADA Tashiyoshi in 2000. In this case, it is different to see through a microscope. The expression is clear whole around. Moreover all patterns are different each other. And the interference stripes emit a characteristic beauty. $T\sum[\sin \left(x^2-y \right)\cos \left(x-y^2 \right)=t]$  Fig.6 T-expression is designed;
$$t=0$$ red $$t=0.9$$ to $$0.02$$ green

$$t=-0.9$$ to $$-0.02$$ blue
Periodic feature is represented with sine, cosine function and two parabolic features cross at right angles. If you reduce the expression Fig.6, you may find another world.
" $$x\sin t + y\cos t$$ " called rotation structure makes rotate a shape with a center of the origin either clockwise or counterclockwise.
Fig.9 $$x\sin t + y\cos t =x^2+y^2$$ ;90 circles make yellow round cookie.
Fig.10 $$x\sin t + y\cos t = x^2+y^2-3$$ ;90 circles make magenta doughnut.    ・・・to be continued