Question

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)

Answer 1

Answer:

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.