Question

Which of these equations is always true?

Answer 1

Answer:

sin(x) = cos(90°-x)

Step-by-step explanation:

Looking at the graphs of sin(x) and cos(x), you can see that the peaks of the graph are separated by a value of pi/2. If you convert that value into degrees, then the two graphs are separated by 90°. Another way of thinking is from the unit circle. sin(x) = 1 at 90°, and cos(x)=1 at 0°. The difference is still 90°