What is #sin(x-90)#?
1 Answer
Dec 17, 2015
Explanation:
Use the sine angle subtraction formula:
#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)#
