Question

Cos(Arctan 5)

Answer 1

first find the angle whose tangent is 5 (that's the arctan 5)

then take the cosine of the result

Answer 2

Yes, I understand the process, however, I'm having trouble finding the angle whose tangent is 5

Answer 3

the arctan might be tan-1 on your calculator

Answer 4

We aren't allowed to use a calc on this problem.

Answer 5

oh OK then draw the right angled triangle

Answer 6

the angle whose tangent is 5 is angle x

work out the hypotenuse usin pythagoras
then cos x = 1 / hypotenuse

Answer 7

Ah yes! I had that in mind but was unsure if that would be correct!
using A^2 + B^2 = c^2
1 + 25 = c^2
c= sqrt26

Cosx = 1/ sqrt26
?

Answer 8

as i expect you knoe tan = opposite /adjacent and c os = adjacent /hypotenuse

Answer 9

yes thats right

Answer 10

Awesome! Thank you so much!

Answer 11

yw