If 0 < f ≤ 90 and cos (22f - 1) = sin (7f + 4), what is the value of f?

f = 3

f = 4

f = 5

f = 6

f = 3

Step-by-step explanation:

Given the equation cos (22f - 1) = sin (7f + 4), the following steps must be followed in order to get the value of f;

From the trigonometry identity, sin (90-theta) = cos theta.

cos (22f-1) = sin (90 - (22f-1))

cos (22f-1) = sin (90-22f+1)

cos (22f-1) = sin (91-22f) ... 3

substituting eqn 3 into the original equation given, we will have;

sin (91-22f) = sin (7f + 4)

91-22f = 7f+4

7f+22f = 91-4

29f = 87

f = 87/29

f = 3