henry is asked to find the exact value of cos 10pi/3. his steps are shown below.

1. subtract 2pi from
10pi/3 as many times as possible:
10pi/3 - 2pi = 4pi/3
2. find the reference angle for 4pi/3 : 3pi/2 - 4pi/3 = pi/6
3. the cosine value for pi/6 is radical 3/2
4. the cosine value is positive because pi/6 is in the first quadrant.

which of the following describes henry's errors?
(following shown in picture)

A) The reference angle should be , and the sign of the value should be negative.

Step-by-step explanation:

cos()

Remove full rotations of 2π until the angle is between 0 and 2.

cos()

Apply the reference angle by finding the angle with equivalent trig values in the first quadrant. Make the expression negative because cosine is negative in the third quadrant.

 -cos()

The exact value of cos() is .

−    

she was supposed to add the hours(38.5) and multiply the amount of money she earned(7.50) resulting in $288.75 .

correct me if i'm wrong and if it is i'm truly sorry.

where is the diagram? shown below where? ?

step-by-step explanation: