Thanks Geno,
I do it the same as Geno but for me I must draw a triangle every time.
Then you can read the values of the triangle. The only other thing you MUST consider is what quadrants it can be in and is the trig ratio going to be positive or negative or either.
If tanΘ=9/5, what is secΘ
tan is poitive so it must be in the 1st or third quadrant.
sec = 1/cos = hyp/adj
cos and therefore sec will be positive in the 1st quad and negative in the 3rd quad.
secθ=±√1065
Our answers are different Geno, I think you have made a little mistake :) secθ=1cosθ
When graphed in the usual x-y plane: tan θ = y/x.
tan θ = y/x and tan θ = 9/5 (if you assume that the angle is in the first quadrant).
The Pythagorean Theorem applies with x2 + y2 = r2 ---> 52 + 92 = r2
---> 25 + 81 = r2 ---> 106 = r2
: r = √106.
sec θ = 1/ cos θ and cos θ = x/r ---> cos θ = 5/√106
---> sec θ = √106/5.
However, the angle could be in the third quadrant which makes y = -9 and x = -5.
r is still √106, but cos θ = -5/√106 and sec θ = - √106/5.
This was corrected after notes from Melody and Alan -- thank you.
Thanks Geno,
I do it the same as Geno but for me I must draw a triangle every time.
Then you can read the values of the triangle. The only other thing you MUST consider is what quadrants it can be in and is the trig ratio going to be positive or negative or either.
If tanΘ=9/5, what is secΘ
tan is poitive so it must be in the 1st or third quadrant.
sec = 1/cos = hyp/adj
cos and therefore sec will be positive in the 1st quad and negative in the 3rd quad.
secθ=±√1065
Our answers are different Geno, I think you have made a little mistake :) secθ=1cosθ