l 43 inches 0 inches 1500 s inches Find the exact value Do n

l 4.3 inches, 0 inches, 1500, s inches, Find the exact value. Do not use a calculator 21 2) sec Find the exact value of the indicated trigor 3) sin 0 sec 0

Solution

You know that sec is 1/cos, right?
So you can find the value of cos(21/4) and invert it.
Since cos repeats every 2, just subtract multiples of 2 to bring it into a more recognisable angle.
Since 2 = 8/4 we get
cos(21/4) = cos(13/4) = cos(5/4)
Now cos(5/4) = -2/2 so
sec(5/4) is the inverse of this = -2/2 = -2