Question

Find the measure of A to the nearest tenth of a degree.

Answer 1

hint:
if we apply the theorem of Carnot, we can write:
\[{36^2} = {42^2} + {71^2} - 2 \cdot 42 \cdot 71 \cdot \cos A\]

Answer 2

then we have:
\[\cos A = \frac{{{{42}^2} + {{71}^2} - {{36}^2}}}{{2 \cdot 42 \cdot 71}} = ...?\]

Answer 3

please complete the computation

Answer 4

ok gimme a sec :)

Answer 5

is it .9237?

Answer 6

@Michele_Laino ?

Answer 7

correct!
Next we have to compute this:
\[A = {\cos ^{ - 1}}\left( {0.9237} \right) = ...?\]

Answer 8

would it be .3931?

Answer 9

please set the mode "deg" on your calculator, first

Answer 10

ok one sec

Answer 11

hmm i cant seem to find it... any hints?

Answer 12

i have a TI-84 plus calculator by texas instruments

Answer 13

do you use a Windows PC?

Answer 14

i have one, but i am using a mac right now

Answer 15

I have a Sharp WriteView calculator, so I give the numerical answer:
A=22.53 degrees, namely \(A=22°\;30'\) approximately

Answer 16

thank you so much!

Answer 17

:)