Answer:
3
Explanation:
We are going to be using cofunction identity cos(90-x)=sin(x).
Apply to either side but not both.
cos(22f − 1) = sin(7f + 4)
sin(90-[22f-1])=sin(7f+4)
90-[22f-1]=7f+4
Distribute
90-22f+1=7f+4
Combine like terms
91-22f=7f+4
Add 22f on both sides
91=29f+4
Subtract 4 on both sides
87=29f
Divide 29 on both sides
3=f
f=3 is between 0 and 90