Use a calculator to find the approximate value of cos-1(0.78).

38.74

Step-by-step explanation:

Hello, I think  I can help you with this.

in a standard calculator you will find the inverse cosine function as the second function of the cosine key

so

step 1

once the calculator is on, press the shift key and then the cosine key, then write the number and close the parenthesis, finally press the equal key

shift ⇒cos⇒0.78⇒)⇒=

in the display you will see( DEG mode)

Now, approximate

      38.7394246\≈38.74

Have a great day.

problem:

f(x) = - 2/3x + 5; f(5/2)

substitute 5/2 in for x:

f(5/2) = -2/3(5/2) + 5

simplify the right side:

f(5/2) = -5/3 + 5

f(5/2) = 10/3

f(5/2) = 10/3

i hope this !

you can first factor out the n to get n(1+5). we know that 1+5 is 6, so we just have 6n.