Evaluate 

where  n  means degrees, not radians.

A circle has area  

and circumference Find 

Determine how many such values of exist for which the following system has a unique

How many such functions f exist which satisfy

for all real numbers  x, y, z?

How many integers n are there such thatn is divisible by 9 and n +1 is divisible by 25?

Let C be the intersection of the plane  x+y –z = 0

and the cone z² = 3x² + y² .

What curve is formed by projecting C onto the xy -plane?

How many positive integers divide (4!)⁴ evenly¹?

1  x divides yevenly

 Which of these things has hit South African journalism?

The new website proved that more money is spent on the environment in China.

When was Africa Check launched?