Praxis II: Math Content Knowledge 100% Correct

Praxis II: Math Content Knowledge 100% Correct sum or product of two rational numbers is rational sum of rational number and irrational number is irrational product of rational number and irrational number is irrational sum or product of two irrational numbers is rational or irrational natural numbers 1, 2, 3, 4, 5, ... composite numbers are positive and not prime the fundamental theorem of algebra any polynomial with complex coefficients has at least one complex root Is matrix multiplication for square matrices commutative, associative, or distributive? only associative and distributive a square matrix has an inverse iff the determinant is nonzero dot product of a matrix must have (m * n) (n * y) multiply row by column M * M^-1 = I determinant of 2 * 2 matrix ad-bc Matrix Operations Row addition Multiply by anything Row switch determinant of 3x3 matrix rewrite first two columns add the Subtract the / permutation formula n! combination formula n!/r! (n-r)! r = # at a time inverse of 2x2 matrix 1/ad-bc [ d -b] [ -c a] x and y are inversely proportional if x increases as y decreases example: x doubles as y halves error = difference of true value and estimated value absolute error = | value - estimated | relative error = | x - x1 | / x Two numbers have same order of magnitude if Big / small is less than 10 1500 has an order of magnitude of 3 because 1.5 x 10^3 the remainder theorem states for a polynomial p(x) and