Cos (2x - 25') = sin 55' 2x - 25' = arc cos (sin 55') 2x - 25' = 35' 2X = 35' + 25' = 60' x = 30 degrees
Cos((2x-25) degrees) = Sin(55 degrees) Sin(55 degrees) = cos(35 degrees) Cos((2x-25) degrees) = cos(35 degrees) 2x - 25 = 35 2x = 10 x = 5
Cos(2x-25)=sin55=cos(90-55)so 2x=60or x=30.
1. Find the sin of 55 Cos (2x-25) = 0.819 2. Add 25 to both sides Cos (2x) = 25.819 3. divide by 2 Cos (x) = 12.90 Find the Cos of 12.90 X = 0.974 I'm not positive about this, but I tried my best.
Cos(90 - 55) = sin(55). The sine of an angle is equal to the cosine of its complement, and vice versa. So 2x - 25 = 90 - 55.
