What is the standard equation of a parabola that opens to the left ?

If f(x) = f (x + p) where p is a positive real number, p is called

Find the equation of the circle, given that A (4, 0) and B (-4 ,0) are the end- points of the diameter.

There are 18 students in a class, the number of ways to group project team included 6 members is

Three-digit odd numbers are formed using 5, 6, 7, 8 and 9.  The number of ways in which repetition digit is allowed is

The number of arrangements 6 persons sit in 3 chairs is

If there are 7 questions in Paper I and 5 questions in Paper II, the number of ways to answer 3 questions from Paper I and 2 questions from Paper II is

If    and    , then   is

Determine the equation of the circle whose radius 3, centered at ( - 4 , 1).

The vector equation of the line through (1, 3, 2) and with direction vector   is