What is $sin (x - 90)$ $sin(x-90)$ ?

Question

92919 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2015-12-17T02:56:39

$- cos (x)$ $-cos(x)$

Use the sine angle subtraction formula:

$sin (α - β) = sin (α) cos (β) - cos (α) sin (β)$ $sin(alpha-beta)=sin(alpha)cos(beta)-cos(alpha)sin(beta)$

Therefore,

$sin(x-90˚)=sin(x)cos(90˚)-cos(x)sin(90˚)$

$=sin(x)(0)-cos(x)(1)$

$=-cos(x)$

What is sin(x-90)sin(x−90)sin(x-90)?