Question

Can anyone teach me how to do these kinds of problems please?:
evaluate cos(arctan(3/4))

Answer 1

ok i will help u

Answer 2

others:
evaluate cos(2pi+arctan4/3)

Answer 3

sec(t)^2 - tan(t)^2 = 1
sec(t) = 1 / cos(t)


sec(arctan(3/4))^2 - tan(arctan(3/4))^2 = 1
sec(arctan(3/4))^2 - (3/4)^2 = (4/4)^2
sec(arctan(3/4))^2 - 9/16 = 16/16
sec(arctan(3/4))^2 = 25/16
sec(arctan(3/4)) = 5/4
1/sec(arctan(3/4)) = 1 / (5/4)
cos(arctan(3/4) = 4/5

Answer 4

do this help u

Answer 5

@cindylouhoo97 do this help uuu

Answer 6

wow I would have drawn a picture and used pythagoras