03: Use substitution to show that x = is a solution to the equation 4 cos (x) - 1 = 0. Show

all of your work (do not use a calculator)

Step-by-step explanation:

4cos x - 1 = 0 is equivalent to 4cos x = 1 and then to cos x = 1/4.

The cosine function is defined as cos x = (adjacent side) / (hypotenuse).

Here cos x = 1/4. To find the angle x, we use the inverse cosine function:

x = arccos (1/4). For the angle x, the adjacent side length is 1 and the hypotenuse length is 4.