Question

pls. explain why there is no real number è that satisfies ither sinè=2 or cos è=2.

Answer 1

In trigonometric terms,

sin(x) is defined as
sin(x)=opposite/hypotenuse.
Since the hypotenuse is the longest side of a right triangle, the value of sin(x) can approach 1, but cannot exceed one.
A similar argument can be made for cos(x).