Question

If sin(Ф)=3/5, and cos(Ф)=-4/5, which of the following is true?

a.) sin((π/2)-Ф)= 4/5
b.) cos((π/2)-Ф)=-3/5

Answer 1

Explanation:

b.) cos((π/2)-Ф)=-3/5 is true because :

cos((π/2)-Ф)= sin(Ф)