Angles a and b are the two acute angles in a right triangle. use the relationship between sine and cosine to find the value of b if b < α. sin(7x − 15) = cos(3x + 5)

In order for the sine and cosine to be equal, the angles must be complementary

sin (7x-15) = cos (3x+5)

7x-15+3x+5 =90 (because sum of both angles a and b must be 90)

10x -10 = 90

10x = 100

x =10

One angle = 7x-15= 7*10-15 = 70-15 =55

Other angle = 3x +5 = 3*10+5 = 30+5 = 35

Since B is less than A, A = 55 degrees and B = 35 degrees

Since we need B, B = 35 degrees

none of the above.

for one of the equations to be used in the process, there has to be a term in the equation since squared is .

since there is only a term in the first equation, we cannot derive a from completing the square.

solving with completing the square