A: because "reflection across the y axis then across the x axis is the only option that does not work"
Answer: Option C is correct
Step-by-step explanation:
We know tha tCos(A-B) = cosA cosB + sinAsinB
Plugging A = 180 and B = Ф
cos(180-Ф)= cos180cosФ+sin180sinФ
= (-1) cosФ+ (0) sinФ [ since cos180=-1 and sin180 =0]
= -cosФ + 0
= -cosФ
Therefore option C is the correct answer.
It must be true that one of the numbers is negative. Hope that helps!!
It’s b, Bc it is :) it really is
