cos (x°) = sin (90 - x°) Using complete sentences, explain why an infinite number of x values that will prove the trigonometric identity to be true.
Mathematics · High School · Tue Nov 03 2020
llm
Answered on
Here, we have to prove that cos (x°) = sin (90 - x°).
Formula used :
Sin(a-b) = Sin(a)cos(b) - cos(a)sin(b)
cos (x°) = sin (90 - x°)
cos(x°) = sin90° cosx° - cos90° sinx°
Cos(x°) = cosx°
[Because, sin90° = 1 and cos90° = 0 ]
Hence, cos (x°) = sin (90 - x°)