Sine and cosine are cofunctions of each other. The cosine of 90-x should be the same as the sine of x. This implies that graph of sine function is the same as shifting the graph of the cosine
Notes on THE EQUATIONS IN TRIGONOMETRY
4.10) Quiz 5: Answers – Trigonometry – Edexcel GCSE Maths Higher
Prove that Sin (90 + x) = Cos x - Maths - Introduction to
Misc 10 - sin x = 1/4, find sin x/2 , cos x/2, tan x/2 - Chapter 3
4.4 Solving equations, Trigonometry
Cofunction Calculator
Proof of sin(90-x) = cos x and cos(90-x) = sin x
Complementary Properties of Trig Ratios
How does cos(90+x)=-sinx? - Quora
Right Triangle Trigonometry