What happens to the decimal point each time we multiply a decimal number by 10

The vector matrix [2/7] is dilated by a favor of 1.5 and then reflected across the x axis. if the resulting matrix is [a/b] then a= and b=

One expression below in undefined, and the other expression has a well defined value. which expression is undefined and explain why it has no value. which expression is defined? what is the value of that expression and how do you know? what is a different expression using a trig inverse function that is also undefined?

G(x) = 2 sin(2x - π) + 4. using complete sentences, explain how to find the minimum value for the function.