Find the wrong piece in each formula

Exercise and reference answers

Questions

1. Statement parts

   1. cos(A + B)
   2. =
   3. cos A cos B
   4. +
   5. sin A sin B

   Correction

   -

   Incorrect part

   +

2. Statement parts

   1. sin(A - B)
   2. =
   3. sin A sin B
   4. -
   5. cos A sin B

   Correction

   sin A cos B

   Incorrect part

   sin A sin B

3. Statement parts

   1. tan(A + B)
   2. =
   3. (tan A + tan B)
   4. /
   5. (1 + tan A tan B)

   Correction

   (1 - tan A tan B)

   Incorrect part

   (1 + tan A tan B)

4. Statement parts

   1. sin(2x)
   2. =
   3. 2
   4. sin x
   5. tan x

   Correction

   cos x

   Incorrect part

   tan x

Instructions

Tap the one piece that makes the formula wrong.

Explanation