50 likes | 153 Views
3.8 Stuff. A quantity y is said to vary directly as the quantity x , or y is directly proportional to x , if there is a constant k such that y = kx This constant is called the constant of variation. 3.8 Stuff.
E N D
3.8 Stuff • A quantity y is said to vary directly as the quantity x, or y is directly proportional to x, if there is a constant k such that y = kx • This constant is called the constant of variation.
3.8 Stuff • “A quantity yvaries directly as the nth power of x” means that y = kxn where k is a nonzero constant and n > 0.
3.8 Stuff • A quantity yvaries inversely as the quantity x, or y is inversely proportional to x, if where k is a nonzero constant.
3.8 Stuff • “A quantity yvaries inversely as the nth power of x” means that where k is a nonzero constant and n > 0.
3.8 Stuff • The expression zvaries jointly as the nth power of x and the mth power of y means that z = kxnym for some nonzero constant k. • Finally, combinations of direct and / or inverse variation may occur. This is referred to as combined variation.