- Defination of primary and secondary standard substance?

Discover Questions

Why is it impossible to tile a plane with thesepolygons located at each vertex: a regular hexagon, a square, and three equalateral triangles? HOW TO FIND GRAMS.. PLEASE? In regression equation, i don't know question No.2? To increase of semiconductor .................. with temperature
a.increase b.decrease c.cant's say D.none of the above? The point (4,4) lies on a circle whose center is at (0,1). How do I write the standard form of the equation of this circle?