Answer:
If A is between the angles 90° and 180°, and we know that:
Sin(A) = 4/7.
But here we have an obvious problem, in the second quadrant, Sin(X) can only have negative values, and we know that 4/7 is a positive number
This means that the actual value of A is not a real value.
If we use the relation:
Asin(Sin(A)) = A = Asin(4/7) = 37°
We would find that A must be smaller than 90°.
And for the periodicity of the trigonometric functions, the next possible value for A will be 37° + 360° = 397°, that is bigger than 180°
And as the Value of A does not exist, the same happens for Cos(A) and tan(A)
