Question

Help?
An acute angle θ is in a right triangle with cos θ = 2/3. What is the value of sec θ?

Answer 1

If the cos is 2/3, that means that adj. side is 2, and the hyp. is 3, right? That would mean the third side would have to be the sqrt of 13... Right?

Answer 2

@surjithayer

Answer 3

\(\bf recall\implies sec(\theta)=\cfrac{1}{cos(\theta)}\)

Answer 4

I can't figure that out until I figure out the third side. Not a single of of the answer choices have sqrt of 13.. What am I doing wrong?

Answer 5

\(\bf cos(\theta)=\cfrac{{\color{blue}{ \square }}}{{\color{red}{ \square }}}\qquad sec(\theta)=\cfrac{{\color{red}{ \square }}}{{\color{blue}{ \square }}}\)

Answer 6

hmm

Answer 7

Oh, wait. Cos is adj/hp, so I do 2^2 + b^2=3^2. 4+b=9 So the third side is sqrt of 5. My bad.

Answer 8

Actually, if I had paid attention, I din't even need the third side... cos is the opposite of sec, so it's 3/2. Right?

Answer 9

yeap

Answer 10

Thanks, hun. :P Sorry I'm slow sometimes. Haha. God bless you!