Solve for x:
cos(x) + sec(x) = 1
Multiply both sides of cos(x) + sec(x) = 1 by cos(x):
1 + cos^2(x) = cos(x)
Subtract cos(x) from both sides:
1 - cos(x) + cos^2(x) = 0
Subtract 1 from both sides:
cos^2(x) - cos(x) = -1
Add 1/4 to both sides:
1/4 - cos(x) + cos^2(x) = -3/4
Write the left hand side as a square:
(cos(x) - 1/2)^2 = -3/4
Take the square root of both sides:
cos(x) - 1/2 = (i sqrt(3))/2 or cos(x) - 1/2 = 1/2 (-i) sqrt(3)
Add 1/2 to both sides:
cos(x) = 1/2 + (i sqrt(3))/2 or cos(x) - 1/2 = 1/2 (-i) sqrt(3)
Take the inverse cosine of both sides:
x = cos^(-1)(1/2 + (i sqrt(3))/2) + 2 π n_1 for n_1 element Z or x = 2 π n_2 - cos^(-1)(1/2 + (i sqrt(3))/2) for n_2 element Z
or cos(x) - 1/2 = 1/2 (-i) sqrt(3)
Add 1/2 to both sides:
x = cos^(-1)(1/2 + (i sqrt(3))/2) + 2 π n_1 for n_1 element Z
or x = 2 π n_2 - cos^(-1)(1/2 + (i sqrt(3))/2) for n_2 element Z
or cos(x) = 1/2 - (i sqrt(3))/2
Take the inverse cosine of both sides:
Answer: |
| x = cos^(-1)(1/2 + (i sqrt(3))/2) + 2 π n_1 for n_1 element Z
or x = 2 π n_2 - cos^(-1)(1/2 + (i sqrt(3))/2) for n_2 element Z
or x = cos^(-1)(1/2 - (i sqrt(3))/2) + 2 π n_3 for n_3 element Z or x = 2 π n_4 - cos^(-1)(1/2 - (i sqrt(3))/2) for n_4 element Z