Question

The degree measure of an angle in a right triangle is x, and sin x =

Which of the following expressions are also equal to
? Select all that apply.
A. Cos(x)
B. Cos(x - 459)
C. cos(90° - x)
D. Cos(60° - x)
E. COS(45° - x)

Answer 1

Explanation:

I feel there is important information lost in the way you provided the problem statement.

e.g. "... also equal to ?"

equal to what ?

sin x = what ?

so, I can only guess some things.

answer C is definitely correct for any angle up to 180 degrees.

answer A is only correct for an angle of 45 or 225 degrees, where sin(x) and cos(x) are both 1/sqrt(2) or both -1/sqrt(2).

answer B is always wrong (459 degrees is no special number, this is a full circle of 360 degrees and then additional 99 degrees there is no special relationship between sine and cosine for 99 degrees, so sine and cosine cannot have the same value for any x).

answer D is always wrong, as there is always a 30 degree difference between the arguments for sine and cosine, and that can never lead to an equal value.

answer E is also always wrong, as these 45 degrees difference also block equal values.