\(20 = 15cos({π \over 30}(x - 30)) +18\)
The answers are 16.3 and 43.7. How can I get those numbers?
Make sure your calculator is in 'radian' mode:
2= 15 cos(pi/30(x-30))
2/15 = cos (pi/30(x-30))
arcos 2/15 = 1.437 = pi/30(x-30) Now can you solve for 'x' ?
You didn't give a range over which to find x arcos 2/15 also = -1.437
so -1.437 = pi/30 (x-30) Solve for 'x'