Why is the circumference formula more accurate than actually measuring around the circle?

How do you create a data set with 8 points in it that has a mean of approximately 10 and a standard deviation of approximately 1?

Evaluate the discriminant of each equation. tell how many solutions each equation has and whether the solutions are real or imaginary. x^2 - 4x - 5 = 0

If log(a) = 1.2 and log(b)= 5.6, what is log(a/b)? a. 4.4b. 6.8c. not enough informationd. -4.4