A formula is a rule that links variables and can be written using mathematical symbols. Substitute the given values for the length of one side (12) and the number of sides (5). Follow the formula ...

Excel gives the answer 10. If you have a mathematical background, you’ll know why Excel gives a different answer to such a simple calculation — and why, technically, Excel is right. If you don’t have ...

For ax 2 + bx + c = 0, (α, β) = [–b ± √(b 2 – 4ac)]/2ac, where α and β are the roots of the equation. Sum of roots = –b/a Product of roots = c/a If roots of a quadratic equation are given, then the ...