MATH 143 - Unit 1

What is the distance formula from point A to point B?

d(A, B) = √(x₂−x₁)²+(y₂−y)²

What is the distance formula for a circle’s radius?

r = √(x-h)²+(y-k)²

What is the standard form of a circle?

(x-h)²+(y-k)²=r²

If |x| = a

then x = a or x = -a

if |x| < a

then -a < x < a (-a, a)

if |x| > a

then -a < x or x > a (-∞, -a) ∪ (a, ∞)

What is the correct form for a complex number?

a + bi