Question

Can someone explain me on how to solve this?
tan[Arc cos(2/5)]

Answer 1

how? :D

Answer 2

Well, we could just use a triangle. This question is kind of like asking, what is the tangent of a triangle that has a cosine of 2/5. A bit long winded, but thats kinda what we're doing. So you know what sides of a triangle cosine correspond to?

Answer 3

i don't get it. :/

Answer 4

Alright, I can explain further. But do you know what sides of a triangle cosine refers to? I mean opposite, adjacent, hypotenuse. Would you happen to know?

Answer 5

yes :D

Answer 6

adj/hyp

Answer 7

Right. So since cosine is adjacent over hypotenuse, we can say that 2/5 represents adjacent over hypotenuse. 2 would be the adjacent side of a triangle and 5 would be the hypotenuse



So our problem tan(arccos2/5)
This question means if we have a triangle, like above, that has a cosine of 2/5. What is the tangent of that triangle. Make a little more sense?

Answer 8

ohhh, so it would be √21 /2 ?

Answer 9

Bingo! ^_^

Answer 10

then how is it in radians? :))

Answer 11

Same answer xD

Answer 12

in degrees* ?

Answer 13

Same. It doesnt matter for this problem, believe it or not.

Answer 14

Ohhh. okay okay, thank you for that! :D

Answer 15

yeah, np ^_^