The point (3, -4) is on the terminal side of an angle θ . What is cos θ?

Question

misty1212 · Answer

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misty1212 · Answer

find the  hypotenuse of that right triangle, lets call it $h$
it will be $\cos(\theta)=\frac{3}{h}$

misty1212 · Answer

the hypotenuse you can do with your eyeballs if you remember the mother of all right triangles, the 3 - 4 - 5  right triangle
or you could use pythagoras if you do not remember that one

anonymous · Answer

Through high school ive had sucky math teachers, so i barely learned anything. So, im having to take online classes and im a visual learner and dont know how to do any of this. Its so confusing

misty1212 · Answer

what you need to know for this is that the cosine is the first coordinate divided by the length of the hypotenuse

misty1212 · Answer

you are told that the first coordinate is 3 so that is your numerator
also the other leg of the triangle has length 4
that means, by pythangoras, since 
$$3^2+4^2=h^2$$  you have $$9+16=h^2\
25=h^2\
5=h$$

anonymous · Answer

here are the answer choices 
a) - 3/5
b) 3/5
c)  -3/4
D) 3/4 
E) 3

misty1212 · Answer

ok which one is it?

anonymous · Answer

b

misty1212 · Answer

yes