2014 · Q76
If sin (A + B) = 1, where 0 < B < 45°, then what is cos (A - B) equal to?
Elementary MathematicsTrigonometry
- Asin 2B
- Bsin B
- Ccos 2B
- Dcos B
Explanation
A + B = 90°; cos(A - B) = cos(90° - 2B) = sin 2B.
If sin (A + B) = 1, where 0 < B < 45°, then what is cos (A - B) equal to?
Explanation
A + B = 90°; cos(A - B) = cos(90° - 2B) = sin 2B.