Back to the studio New seed 4 problems · seed 2VR9HHZPBZ0FK4E2GWGSR3YCJ0

True or False?

A real identity — half of them subtly broken. You guess; the verdict is checked, not assumed.

Randomly
equations.identity
Name Class Date
  1. 1.
    sin(x)^2 + cos(x)^2 = 2
  2. 2.
    ln(a/b) = ln(a) - ln(b)
  3. 3.
    cos(3x) = 4cos(x)^3 - 4cos(x)
  4. 4.
    cos(a + b) = cos(a)cos(b) - sin(a)cos(b)

Answer key

True or False? — seed 2VR9HHZPBZ0FK4E2GWGSR3YCJ0

Randomly
equations.identity
  1. 1. False — the coefficient 1 became 2; it should read sin(x)^2 + cos(x)^2 = 1
  2. 2. True
  3. 3. False — the coefficient 3 became 4; it should read cos(3x) = 4cos(x)^3 - 3cos(x)
  4. 4. False — a sin became a cos; it should read cos(a + b) = cos(a)cos(b) - sin(a)sin(b)