P(not 5) =5/6 and P(5) = 1/6 If the first 5 is rolled on the 5th roll then the first four rolls were not 5 P(5 on fifth roll) = 5/6 x 5/6 x 5/6 x 5/6 x 1/6 = 5^4/6^5 = 625/7776 = 0.080375...
If the x is squared, the parabola is vertical (opens up or down). If the y is squared, it is horizontal (opens left or right). If a is positive, the parabola opens up or to the right. If it is negative, it opens down or to the left.
