One meaning of forceful is all about physical strength: The forceful throw carried the football past the goalposts. Another way to be forceful is to be emphatic or vehement: The child's forceful refusal to go to bed could not be ignored by the sleepy babysitter. Forceful literally means full of force, and force comes from the Latin fortis, strong, firm, or steadfast.
In addition to being the 18th letter of the Greek alphabet, sigma also means 'sum' and 'deviation' in the mathematics world. Learn what each symbol looks like and how each formula works. High School Precalculus: Homework Help Resource / Math Courses.
Pi is the number used to find the circumference or area of a circle. It is also used to calculate the surface area and volume of a sphere, cylinder, and cone.