Question

cos(2arccos1/3)=?
please can you answear?

Answer 1

\[\large \cos\left(2\color{royalblue}{\arccos\frac{1}{3}}\right)\]

\[\large \color{royalblue}{\arccos\frac{1}{3}=\theta} \qquad\rightarrow\qquad \cos \theta=\frac{1}{3}=\frac{adjacent}{hypotenuse}\]

We can draw a triangle to express this Trig function.

Answer 2

Since this is your first question I feel I should ask,
Is the formatted math text showing up ok on your screen?

If you're using Internet Explorer it might just show up as a bunch of ugly code.

Answer 3

no no thanks a lot bro

Answer 4

hmm? :o

Answer 5

Anyway, we can label the sides of our triangle given cosine of the angle.Then we want to use the Pythagorean Theorem to solve for the missing side.