Two are true, one is not

Exercise and reference answers

Questions

1. False statement

   1 + tan²x = cosec²x

   Statements

   1. cos²x + sin²x = 1
   2. 1 + tan²x = sec²x
   3. 1 + tan²x = cosec²x

2. False statement

   cosine is odd

   Statements

   1. cosine is odd
   2. sine is odd
   3. cosine is even

3. False statement

   cos(x+y) uses a plus

   Statements

   1. cos(x+y) uses a minus
   2. cos(x+y) uses a plus
   3. sin(x+y) uses a plus

Explanation